diff --git a/substrate/bin/node/executor/tests/basic.rs b/substrate/bin/node/executor/tests/basic.rs
index 26c04efe4999177cf14ac032cf310bc2a368ebae..f007ba41ccc6185a03e6c49d6c63fd2e4593c249 100644
--- a/substrate/bin/node/executor/tests/basic.rs
+++ b/substrate/bin/node/executor/tests/basic.rs
@@ -329,7 +329,7 @@ fn full_native_block_import_works() {
 		let events = vec![
 			EventRecord {
 				phase: Phase::ApplyExtrinsic(0),
-				event: Event::frame_system(frame_system::RawEvent::ExtrinsicSuccess(
+				event: Event::frame_system(frame_system::Event::ExtrinsicSuccess(
 					DispatchInfo { weight: timestamp_weight, class: DispatchClass::Mandatory, ..Default::default() }
 				)),
 				topics: vec![],
@@ -350,7 +350,7 @@ fn full_native_block_import_works() {
 			},
 			EventRecord {
 				phase: Phase::ApplyExtrinsic(1),
-				event: Event::frame_system(frame_system::RawEvent::ExtrinsicSuccess(
+				event: Event::frame_system(frame_system::Event::ExtrinsicSuccess(
 					DispatchInfo { weight: transfer_weight, ..Default::default() }
 				)),
 				topics: vec![],
@@ -381,7 +381,7 @@ fn full_native_block_import_works() {
 		let events = vec![
 			EventRecord {
 				phase: Phase::ApplyExtrinsic(0),
-				event: Event::frame_system(frame_system::RawEvent::ExtrinsicSuccess(
+				event: Event::frame_system(frame_system::Event::ExtrinsicSuccess(
 					DispatchInfo { weight: timestamp_weight, class: DispatchClass::Mandatory, ..Default::default() }
 				)),
 				topics: vec![],
@@ -404,7 +404,7 @@ fn full_native_block_import_works() {
 			},
 			EventRecord {
 				phase: Phase::ApplyExtrinsic(1),
-				event: Event::frame_system(frame_system::RawEvent::ExtrinsicSuccess(
+				event: Event::frame_system(frame_system::Event::ExtrinsicSuccess(
 					DispatchInfo { weight: transfer_weight, ..Default::default() }
 				)),
 				topics: vec![],
@@ -427,7 +427,7 @@ fn full_native_block_import_works() {
 			},
 			EventRecord {
 				phase: Phase::ApplyExtrinsic(2),
-				event: Event::frame_system(frame_system::RawEvent::ExtrinsicSuccess(
+				event: Event::frame_system(frame_system::Event::ExtrinsicSuccess(
 					DispatchInfo { weight: transfer_weight, ..Default::default() }
 				)),
 				topics: vec![],
diff --git a/substrate/bin/node/executor/tests/fees.rs b/substrate/bin/node/executor/tests/fees.rs
index ed354d553448acfd98c750543b2c710a833e6943..9d83610b689dec03e6b7b6739db4dca8524bef1a 100644
--- a/substrate/bin/node/executor/tests/fees.rs
+++ b/substrate/bin/node/executor/tests/fees.rs
@@ -17,7 +17,7 @@
 
 use codec::{Encode, Joiner};
 use frame_support::{
-	StorageValue, StorageMap,
+	StorageValue,
 	traits::Currency,
 	weights::{GetDispatchInfo, constants::ExtrinsicBaseWeight, IdentityFee, WeightToFeePolynomial},
 };
diff --git a/substrate/bin/node/executor/tests/submit_transaction.rs b/substrate/bin/node/executor/tests/submit_transaction.rs
index c628826c62befee766ebb58a620cb2484a00e9ef..ff483d9ecd8cd9740201796a9cb67ae65519eae7 100644
--- a/substrate/bin/node/executor/tests/submit_transaction.rs
+++ b/substrate/bin/node/executor/tests/submit_transaction.rs
@@ -217,7 +217,6 @@ fn should_submit_signed_twice_from_all_accounts() {
 #[test]
 fn submitted_transaction_should_be_valid() {
 	use codec::Encode;
-	use frame_support::storage::StorageMap;
 	use sp_runtime::transaction_validity::{TransactionSource, TransactionTag};
 	use sp_runtime::traits::StaticLookup;
 
diff --git a/substrate/frame/balances/src/tests.rs b/substrate/frame/balances/src/tests.rs
index 90e8e0d7cbdcf3dc89308714fb185505b6685cb4..7a1b57a7b4db1e8892c30699bf4483367cce4978 100644
--- a/substrate/frame/balances/src/tests.rs
+++ b/substrate/frame/balances/src/tests.rs
@@ -737,7 +737,7 @@ macro_rules! decl_tests {
 					assert_eq!(
 						events(),
 						[
-							Event::system(system::RawEvent::NewAccount(1)),
+							Event::system(system::Event::NewAccount(1)),
 							Event::balances(RawEvent::Endowed(1, 100)),
 							Event::balances(RawEvent::BalanceSet(1, 100, 0)),
 						]
@@ -749,7 +749,7 @@ macro_rules! decl_tests {
 						events(),
 						[
 							Event::balances(RawEvent::DustLost(1, 99)),
-							Event::system(system::RawEvent::KilledAccount(1))
+							Event::system(system::Event::KilledAccount(1))
 						]
 					);
 				});
@@ -766,7 +766,7 @@ macro_rules! decl_tests {
 					assert_eq!(
 						events(),
 						[
-							Event::system(system::RawEvent::NewAccount(1)),
+							Event::system(system::Event::NewAccount(1)),
 							Event::balances(RawEvent::Endowed(1, 100)),
 							Event::balances(RawEvent::BalanceSet(1, 100, 0)),
 						]
@@ -777,7 +777,7 @@ macro_rules! decl_tests {
 					assert_eq!(
 						events(),
 						[
-							Event::system(system::RawEvent::KilledAccount(1))
+							Event::system(system::Event::KilledAccount(1))
 						]
 					);
 				});
diff --git a/substrate/frame/balances/src/tests_local.rs b/substrate/frame/balances/src/tests_local.rs
index 2cbf46709275a066e1fe9dcc7fc2c90c69c3ed42..762ebe871b3e8294009b73c9b9c9fe1a51e5af64 100644
--- a/substrate/frame/balances/src/tests_local.rs
+++ b/substrate/frame/balances/src/tests_local.rs
@@ -170,7 +170,7 @@ fn emit_events_with_no_existential_deposit_suicide_with_dust() {
 			assert_eq!(
 				events(),
 				[
-					Event::system(system::RawEvent::NewAccount(1)),
+					Event::system(system::Event::NewAccount(1)),
 					Event::balances(RawEvent::Endowed(1, 100)),
 					Event::balances(RawEvent::BalanceSet(1, 100, 0)),
 				]
@@ -187,7 +187,7 @@ fn emit_events_with_no_existential_deposit_suicide_with_dust() {
 				events(),
 				[
 					Event::balances(RawEvent::DustLost(1, 1)),
-					Event::system(system::RawEvent::KilledAccount(1))
+					Event::system(system::Event::KilledAccount(1))
 				]
 			);
 		});
diff --git a/substrate/frame/contracts/src/tests.rs b/substrate/frame/contracts/src/tests.rs
index 965cb7e49a0a4bd7201f02a5fe7813a355de02bc..96bcf99bf8e81e4bafecf5aaf622b07f887b8b82 100644
--- a/substrate/frame/contracts/src/tests.rs
+++ b/substrate/frame/contracts/src/tests.rs
@@ -475,7 +475,7 @@ fn instantiate_and_call_and_deposit_event() {
 			pretty_assertions::assert_eq!(System::events(), vec![
 				EventRecord {
 					phase: Phase::Initialization,
-					event: MetaEvent::system(frame_system::RawEvent::NewAccount(ALICE.clone())),
+					event: MetaEvent::system(frame_system::Event::NewAccount(ALICE.clone())),
 					topics: vec![],
 				},
 				EventRecord {
@@ -492,7 +492,7 @@ fn instantiate_and_call_and_deposit_event() {
 				},
 				EventRecord {
 					phase: Phase::Initialization,
-					event: MetaEvent::system(frame_system::RawEvent::NewAccount(addr.clone())),
+					event: MetaEvent::system(frame_system::Event::NewAccount(addr.clone())),
 					topics: vec![],
 				},
 				EventRecord {
@@ -653,7 +653,7 @@ fn test_set_rent_code_and_hash() {
 			assert_eq!(System::events(), vec![
 				EventRecord {
 					phase: Phase::Initialization,
-					event: MetaEvent::system(frame_system::RawEvent::NewAccount(ALICE)),
+					event: MetaEvent::system(frame_system::Event::NewAccount(ALICE)),
 					topics: vec![],
 				},
 				EventRecord {
@@ -1235,7 +1235,7 @@ fn restoration(test_different_storage: bool, test_restore_to_with_dirty_storage:
 			assert_eq!(System::events(), vec![
 				EventRecord {
 					phase: Phase::Initialization,
-					event: MetaEvent::system(frame_system::RawEvent::NewAccount(ALICE)),
+					event: MetaEvent::system(frame_system::Event::NewAccount(ALICE)),
 					topics: vec![],
 				},
 				EventRecord {
@@ -1390,7 +1390,7 @@ fn restoration(test_different_storage: bool, test_restore_to_with_dirty_storage:
 							},
 							EventRecord {
 								phase: Phase::Initialization,
-								event: MetaEvent::system(frame_system::RawEvent::NewAccount(CHARLIE)),
+								event: MetaEvent::system(frame_system::Event::NewAccount(CHARLIE)),
 								topics: vec![],
 							},
 							EventRecord {
@@ -1400,7 +1400,7 @@ fn restoration(test_different_storage: bool, test_restore_to_with_dirty_storage:
 							},
 							EventRecord {
 								phase: Phase::Initialization,
-								event: MetaEvent::system(frame_system::RawEvent::NewAccount(addr_django.clone())),
+								event: MetaEvent::system(frame_system::Event::NewAccount(addr_django.clone())),
 								topics: vec![],
 							},
 							EventRecord {
@@ -1440,7 +1440,7 @@ fn restoration(test_different_storage: bool, test_restore_to_with_dirty_storage:
 				assert_eq!(System::events(), vec![
 					EventRecord {
 						phase: Phase::Initialization,
-						event: MetaEvent::system(system::RawEvent::KilledAccount(addr_django.clone())),
+						event: MetaEvent::system(system::Event::KilledAccount(addr_django.clone())),
 						topics: vec![],
 					},
 					EventRecord {
diff --git a/substrate/frame/executive/src/lib.rs b/substrate/frame/executive/src/lib.rs
index 05b4b0f982a0b05bd5b5f1fea31651b8f915717d..df1ae17df613fa4cbfa5516d265e376dd3e74290 100644
--- a/substrate/frame/executive/src/lib.rs
+++ b/substrate/frame/executive/src/lib.rs
@@ -117,7 +117,7 @@
 
 use sp_std::{prelude::*, marker::PhantomData};
 use frame_support::{
-	StorageValue, StorageMap, weights::{GetDispatchInfo, DispatchInfo, DispatchClass},
+	weights::{GetDispatchInfo, DispatchInfo, DispatchClass},
 	traits::{OnInitialize, OnFinalize, OnRuntimeUpgrade, OffchainWorker},
 	dispatch::PostDispatchInfo,
 };
@@ -261,11 +261,11 @@ where
 
 	/// Returns if the runtime was upgraded since the last time this function was called.
 	fn runtime_upgraded() -> bool {
-		let last = frame_system::LastRuntimeUpgrade::get();
+		let last = frame_system::LastRuntimeUpgrade::<System>::get();
 		let current = <System::Version as frame_support::traits::Get<_>>::get();
 
 		if last.map(|v| v.was_upgraded(&current)).unwrap_or(true) {
-			frame_system::LastRuntimeUpgrade::put(
+			frame_system::LastRuntimeUpgrade::<System>::put(
 				frame_system::LastRuntimeUpgradeInfo::from(current),
 			);
 			true
@@ -998,7 +998,7 @@ mod tests {
 		new_test_ext(1).execute_with(|| {
 			RUNTIME_VERSION.with(|v| *v.borrow_mut() = Default::default());
 			// It should be added at genesis
-			assert!(frame_system::LastRuntimeUpgrade::exists());
+			assert!(frame_system::LastRuntimeUpgrade::<Runtime>::exists());
 			assert!(!Executive::runtime_upgraded());
 
 			RUNTIME_VERSION.with(|v| *v.borrow_mut() = sp_version::RuntimeVersion {
@@ -1008,7 +1008,7 @@ mod tests {
 			assert!(Executive::runtime_upgraded());
 			assert_eq!(
 				Some(LastRuntimeUpgradeInfo { spec_version: 1.into(), spec_name: "".into() }),
-				frame_system::LastRuntimeUpgrade::get(),
+				frame_system::LastRuntimeUpgrade::<Runtime>::get(),
 			);
 
 			RUNTIME_VERSION.with(|v| *v.borrow_mut() = sp_version::RuntimeVersion {
@@ -1019,7 +1019,7 @@ mod tests {
 			assert!(Executive::runtime_upgraded());
 			assert_eq!(
 				Some(LastRuntimeUpgradeInfo { spec_version: 1.into(), spec_name: "test".into() }),
-				frame_system::LastRuntimeUpgrade::get(),
+				frame_system::LastRuntimeUpgrade::<Runtime>::get(),
 			);
 
 			RUNTIME_VERSION.with(|v| *v.borrow_mut() = sp_version::RuntimeVersion {
@@ -1030,11 +1030,11 @@ mod tests {
 			});
 			assert!(!Executive::runtime_upgraded());
 
-			frame_system::LastRuntimeUpgrade::take();
+			frame_system::LastRuntimeUpgrade::<Runtime>::take();
 			assert!(Executive::runtime_upgraded());
 			assert_eq!(
 				Some(LastRuntimeUpgradeInfo { spec_version: 1.into(), spec_name: "test".into() }),
-				frame_system::LastRuntimeUpgrade::get(),
+				frame_system::LastRuntimeUpgrade::<Runtime>::get(),
 			);
 		})
 	}
diff --git a/substrate/frame/session/benchmarking/src/lib.rs b/substrate/frame/session/benchmarking/src/lib.rs
index 8f1911c125b8532646a6a93c3ac0eef501efaa88..06dfa3da349438d976d4610d4a181f1d9a3ffcfd 100644
--- a/substrate/frame/session/benchmarking/src/lib.rs
+++ b/substrate/frame/session/benchmarking/src/lib.rs
@@ -28,7 +28,7 @@ use sp_std::vec;
 use frame_benchmarking::benchmarks;
 use frame_support::{
 	codec::Decode,
-	storage::{StorageValue, StorageMap},
+	storage::StorageValue,
 	traits::{KeyOwnerProofSystem, OnInitialize},
 };
 use frame_system::RawOrigin;
diff --git a/substrate/frame/system/src/extensions/check_mortality.rs b/substrate/frame/system/src/extensions/check_mortality.rs
index 8e5fd36e6217a223be896498f0e8c3f48d137a83..f1951baba5d50133f00e6ff0ded91920642fd37b 100644
--- a/substrate/frame/system/src/extensions/check_mortality.rs
+++ b/substrate/frame/system/src/extensions/check_mortality.rs
@@ -17,7 +17,6 @@
 
 use codec::{Encode, Decode};
 use crate::{Config, Module, BlockHash};
-use frame_support::StorageMap;
 use sp_runtime::{
 	generic::Era,
 	traits::{SignedExtension, DispatchInfoOf, SaturatedConversion},
diff --git a/substrate/frame/system/src/extensions/check_nonce.rs b/substrate/frame/system/src/extensions/check_nonce.rs
index c5d0e5242b4848217b17280e6b32d2c8ace218cd..bc48be925bc0d0299488b23513b502c4f380b6c8 100644
--- a/substrate/frame/system/src/extensions/check_nonce.rs
+++ b/substrate/frame/system/src/extensions/check_nonce.rs
@@ -17,10 +17,7 @@
 
 use codec::{Encode, Decode};
 use crate::Config;
-use frame_support::{
-	weights::DispatchInfo,
-	StorageMap,
-};
+use frame_support::weights::DispatchInfo;
 use sp_runtime::{
 	traits::{SignedExtension, DispatchInfoOf, Dispatchable, One},
 	transaction_validity::{
diff --git a/substrate/frame/system/src/extensions/check_weight.rs b/substrate/frame/system/src/extensions/check_weight.rs
index c84c29518593f4ee2bc57a7d4acb820a3c089fca..70116f4b6524bbbc906cb1928f240220bdd4fe34 100644
--- a/substrate/frame/system/src/extensions/check_weight.rs
+++ b/substrate/frame/system/src/extensions/check_weight.rs
@@ -28,7 +28,6 @@ use sp_runtime::{
 use frame_support::{
 	traits::{Get},
 	weights::{PostDispatchInfo, DispatchInfo, DispatchClass, priority::FrameTransactionPriority},
-	StorageValue,
 };
 
 /// Block resource (weight) limit check.
@@ -115,8 +114,8 @@ impl<T: Config + Send + Sync> CheckWeight<T> where
 		let next_weight = Self::check_block_weight(info)?;
 		Self::check_extrinsic_weight(info)?;
 
-		crate::AllExtrinsicsLen::put(next_len);
-		crate::BlockWeight::put(next_weight);
+		crate::AllExtrinsicsLen::<T>::put(next_len);
+		crate::BlockWeight::<T>::put(next_weight);
 		Ok(())
 	}
 
@@ -257,7 +256,7 @@ impl<T: Config + Send + Sync> SignedExtension for CheckWeight<T> where
 
 		let unspent = post_info.calc_unspent(info);
 		if unspent > 0 {
-			crate::BlockWeight::mutate(|current_weight| {
+			crate::BlockWeight::<T>::mutate(|current_weight| {
 				current_weight.sub(unspent, info.class);
 			})
 		}
@@ -465,7 +464,7 @@ mod tests {
 			let normal_limit = normal_weight_limit();
 
 			// given almost full block
-			BlockWeight::mutate(|current_weight| {
+			BlockWeight::<Test>::mutate(|current_weight| {
 				current_weight.set(normal_limit, DispatchClass::Normal)
 			});
 			// will not fit.
@@ -475,7 +474,7 @@ mod tests {
 
 			// likewise for length limit.
 			let len = 100_usize;
-			AllExtrinsicsLen::put(normal_length_limit());
+			AllExtrinsicsLen::<Test>::put(normal_length_limit());
 			assert!(CheckWeight::<Test>(PhantomData).pre_dispatch(&1, CALL, &normal, len).is_err());
 			assert!(CheckWeight::<Test>(PhantomData).pre_dispatch(&1, CALL, &op, len).is_ok());
 		})
@@ -508,7 +507,7 @@ mod tests {
 			let normal = DispatchInfo::default();
 			let normal_limit = normal_weight_limit() as usize;
 			let reset_check_weight = |tx, s, f| {
-				AllExtrinsicsLen::put(0);
+				AllExtrinsicsLen::<Test>::put(0);
 				let r = CheckWeight::<Test>(PhantomData).pre_dispatch(&1, CALL, tx, s);
 				if f { assert!(r.is_err()) } else { assert!(r.is_ok()) }
 			};
@@ -544,7 +543,7 @@ mod tests {
 			let len = 0_usize;
 
 			let reset_check_weight = |i, f, s| {
-				BlockWeight::mutate(|current_weight| {
+				BlockWeight::<Test>::mutate(|current_weight| {
 					current_weight.set(s, DispatchClass::Normal)
 				});
 				let r = CheckWeight::<Test>(PhantomData).pre_dispatch(&1, CALL, i, len);
@@ -570,20 +569,20 @@ mod tests {
 			let base_extrinsic = block_weights().get(DispatchClass::Normal).base_extrinsic;
 
 			// We allow 75% for normal transaction, so we put 25% - extrinsic base weight
-			BlockWeight::mutate(|current_weight| {
+			BlockWeight::<Test>::mutate(|current_weight| {
 				current_weight.set(0, DispatchClass::Mandatory);
 				current_weight.set(256 - base_extrinsic, DispatchClass::Normal);
 			});
 
 			let pre = CheckWeight::<Test>(PhantomData).pre_dispatch(&1, CALL, &info, len).unwrap();
-			assert_eq!(BlockWeight::get().total(), info.weight + 256);
+			assert_eq!(BlockWeight::<Test>::get().total(), info.weight + 256);
 
 			assert!(
 				CheckWeight::<Test>::post_dispatch(pre, &info, &post_info, len, &Ok(()))
 				.is_ok()
 			);
 			assert_eq!(
-				BlockWeight::get().total(),
+				BlockWeight::<Test>::get().total(),
 				post_info.actual_weight.unwrap() + 256,
 			);
 		})
@@ -599,14 +598,14 @@ mod tests {
 			};
 			let len = 0_usize;
 
-			BlockWeight::mutate(|current_weight| {
+			BlockWeight::<Test>::mutate(|current_weight| {
 				current_weight.set(0, DispatchClass::Mandatory);
 				current_weight.set(128, DispatchClass::Normal);
 			});
 
 			let pre = CheckWeight::<Test>(PhantomData).pre_dispatch(&1, CALL, &info, len).unwrap();
 			assert_eq!(
-				BlockWeight::get().total(),
+				BlockWeight::<Test>::get().total(),
 				info.weight + 128 + block_weights().get(DispatchClass::Normal).base_extrinsic,
 			);
 
@@ -615,7 +614,7 @@ mod tests {
 				.is_ok()
 			);
 			assert_eq!(
-				BlockWeight::get().total(),
+				BlockWeight::<Test>::get().total(),
 				info.weight + 128 + block_weights().get(DispatchClass::Normal).base_extrinsic,
 			);
 		})
diff --git a/substrate/frame/system/src/lib.rs b/substrate/frame/system/src/lib.rs
index 0efa511e99b5e9bb9dda8ee4eea768b888d84cee..cdb26623734fdfe61aaa77f81571f8291144342c 100644
--- a/substrate/frame/system/src/lib.rs
+++ b/substrate/frame/system/src/lib.rs
@@ -15,17 +15,17 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//! # System Module
+//! # System Pallet
 //!
-//! The System module provides low-level access to core types and cross-cutting utilities.
+//! The System pallet provides low-level access to core types and cross-cutting utilities.
 //! It acts as the base layer for other pallets to interact with the Substrate framework components.
 //!
-//! - [`system::Config`](./trait.Config.html)
+//! - [`Config`]
 //!
 //! ## Overview
 //!
-//! The System module defines the core data types used in a Substrate runtime.
-//! It also provides several utility functions (see [`Module`](./struct.Module.html)) for other FRAME pallets.
+//! The System pallet defines the core data types used in a Substrate runtime.
+//! It also provides several utility functions (see [`Pallet`]) for other FRAME pallets.
 //!
 //! In addition, it manages the storage items for extrinsics data, indexes, event records, and digest items,
 //! among other things that support the execution of the current block.
@@ -37,15 +37,15 @@
 //!
 //! ### Dispatchable Functions
 //!
-//! The System module does not implement any dispatchable functions.
+//! The System pallet does not implement any dispatchable functions.
 //!
 //! ### Public Functions
 //!
-//! See the [`Module`](./struct.Module.html) struct for details of publicly available functions.
+//! See the [`Pallet`] struct for details of publicly available functions.
 //!
 //! ### Signed Extensions
 //!
-//! The System module defines the following extensions:
+//! The System pallet defines the following extensions:
 //!
 //!   - [`CheckWeight`]: Checks the weight and length of the block and ensure that it does not
 //!     exceed the limits.
@@ -61,34 +61,6 @@
 //!
 //! Lookup the runtime aggregator file (e.g. `node/runtime`) to see the full list of signed
 //! extensions included in a chain.
-//!
-//! ## Usage
-//!
-//! ### Prerequisites
-//!
-//! Import the System module and derive your module's configuration trait from the system trait.
-//!
-//! ### Example - Get extrinsic count and parent hash for the current block
-//!
-//! ```
-//! use frame_support::{decl_module, dispatch};
-//! use frame_system::{self as system, ensure_signed};
-//!
-//! pub trait Config: system::Config {}
-//!
-//! decl_module! {
-//! 	pub struct Module<T: Config> for enum Call where origin: T::Origin {
-//! 		#[weight = 0]
-//! 		pub fn system_module_example(origin) -> dispatch::DispatchResult {
-//! 			let _sender = ensure_signed(origin)?;
-//! 			let _extrinsic_count = <system::Module<T>>::extrinsic_count();
-//! 			let _parent_hash = <system::Module<T>>::parent_hash();
-//! 			Ok(())
-//! 		}
-//! 	}
-//! }
-//! # fn main() { }
-//! ```
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
@@ -113,7 +85,7 @@ use sp_runtime::{
 
 use sp_core::{ChangesTrieConfiguration, storage::well_known_keys};
 use frame_support::{
-	decl_module, decl_event, decl_storage, decl_error, Parameter, debug, storage,
+	Parameter, debug, storage,
 	traits::{
 		Contains, Get, PalletInfo, OnNewAccount, OnKilledAccount, HandleLifetime,
 		StoredMap, EnsureOrigin, OriginTrait, Filter,
@@ -126,6 +98,8 @@ use frame_support::{
 };
 use codec::{Encode, Decode, FullCodec, EncodeLike};
 
+#[cfg(feature = "std")]
+use frame_support::traits::GenesisBuild;
 #[cfg(any(feature = "std", test))]
 use sp_io::TestExternalities;
 
@@ -162,401 +136,132 @@ pub fn extrinsics_data_root<H: Hash>(xts: Vec<Vec<u8>>) -> H::Output {
 /// An object to track the currently used extrinsic weight in a block.
 pub type ConsumedWeight = PerDispatchClass<Weight>;
 
-/// System configuration trait. Implemented by runtime.
-pub trait Config: 'static + Eq + Clone {
-	/// The basic call filter to use in Origin. All origins are built with this filter as base,
-	/// except Root.
-	type BaseCallFilter: Filter<Self::Call>;
-
-	/// Block & extrinsics weights: base values and limits.
-	type BlockWeights: Get<limits::BlockWeights>;
-
-	/// The maximum length of a block (in bytes).
-	type BlockLength: Get<limits::BlockLength>;
-
-	/// The `Origin` type used by dispatchable calls.
-	type Origin:
-		Into<Result<RawOrigin<Self::AccountId>, Self::Origin>>
-		+ From<RawOrigin<Self::AccountId>>
-		+ Clone
-		+ OriginTrait<Call = Self::Call>;
-
-	/// The aggregated `Call` type.
-	type Call: Dispatchable + Debug;
-
-	/// Account index (aka nonce) type. This stores the number of previous transactions associated
-	/// with a sender account.
-	type Index:
-		Parameter + Member + MaybeSerialize + Debug + Default + MaybeDisplay + AtLeast32Bit
-		+ Copy;
-
-	/// The block number type used by the runtime.
-	type BlockNumber:
-		Parameter + Member + MaybeSerializeDeserialize + Debug + MaybeDisplay +
-		AtLeast32BitUnsigned + Default + Bounded + Copy + sp_std::hash::Hash +
-		sp_std::str::FromStr + MaybeMallocSizeOf;
-
-	/// The output of the `Hashing` function.
-	type Hash:
-		Parameter + Member + MaybeSerializeDeserialize + Debug + MaybeDisplay + SimpleBitOps + Ord
-		+ Default + Copy + CheckEqual + sp_std::hash::Hash + AsRef<[u8]> + AsMut<[u8]> + MaybeMallocSizeOf;
-
-	/// The hashing system (algorithm) being used in the runtime (e.g. Blake2).
-	type Hashing: Hash<Output = Self::Hash>;
-
-	/// The user account identifier type for the runtime.
-	type AccountId: Parameter + Member + MaybeSerializeDeserialize + Debug + MaybeDisplay + Ord
-		+ Default;
-
-	/// Converting trait to take a source type and convert to `AccountId`.
-	///
-	/// Used to define the type and conversion mechanism for referencing accounts in transactions.
-	/// It's perfectly reasonable for this to be an identity conversion (with the source type being
-	/// `AccountId`), but other modules (e.g. Indices module) may provide more functional/efficient
-	/// alternatives.
-	type Lookup: StaticLookup<Target = Self::AccountId>;
-
-	/// The block header.
-	type Header: Parameter + traits::Header<
-		Number = Self::BlockNumber,
-		Hash = Self::Hash,
-	>;
-
-	/// The aggregated event type of the runtime.
-	type Event: Parameter + Member + From<Event<Self>> + Debug;
-
-	/// Maximum number of block number to block hash mappings to keep (oldest pruned first).
-	type BlockHashCount: Get<Self::BlockNumber>;
-
-	/// The weight of runtime database operations the runtime can invoke.
-	type DbWeight: Get<RuntimeDbWeight>;
-
-	/// Get the chain's current version.
-	type Version: Get<RuntimeVersion>;
-
-	/// Provides information about the pallet setup in the runtime.
-	///
-	/// Expects the `PalletInfo` type that is being generated by `construct_runtime!` in the
-	/// runtime.
-	///
-	/// For tests it is okay to use `()` as type, however it will provide "useless" data.
-	type PalletInfo: PalletInfo;
-
-	/// Data to be associated with an account (other than nonce/transaction counter, which this
-	/// module does regardless).
-	type AccountData: Member + FullCodec + Clone + Default;
-
-	/// Handler for when a new account has just been created.
-	type OnNewAccount: OnNewAccount<Self::AccountId>;
-
-	/// A function that is invoked when an account has been determined to be dead.
-	///
-	/// All resources should be cleaned up associated with the given account.
-	type OnKilledAccount: OnKilledAccount<Self::AccountId>;
-
-	type SystemWeightInfo: WeightInfo;
-
-	/// The designated SS85 prefix of this chain.
-	///
-	/// This replaces the "ss58Format" property declared in the chain spec. Reason is
-	/// that the runtime should know about the prefix in order to make use of it as
-	/// an identifier of the chain.
-	type SS58Prefix: Get<u8>;
-}
-
-pub type DigestOf<T> = generic::Digest<<T as Config>::Hash>;
-pub type DigestItemOf<T> = generic::DigestItem<<T as Config>::Hash>;
-
-pub type Key = Vec<u8>;
-pub type KeyValue = (Vec<u8>, Vec<u8>);
-
-/// A phase of a block's execution.
-#[derive(Encode, Decode, RuntimeDebug)]
-#[cfg_attr(feature = "std", derive(Serialize, PartialEq, Eq, Clone))]
-pub enum Phase {
-	/// Applying an extrinsic.
-	ApplyExtrinsic(u32),
-	/// Finalizing the block.
-	Finalization,
-	/// Initializing the block.
-	Initialization,
-}
-
-impl Default for Phase {
-	fn default() -> Self {
-		Self::Initialization
-	}
-}
-
-/// Record of an event happening.
-#[derive(Encode, Decode, RuntimeDebug)]
-#[cfg_attr(feature = "std", derive(Serialize, PartialEq, Eq, Clone))]
-pub struct EventRecord<E: Parameter + Member, T> {
-	/// The phase of the block it happened in.
-	pub phase: Phase,
-	/// The event itself.
-	pub event: E,
-	/// The list of the topics this event has.
-	pub topics: Vec<T>,
-}
-
-/// Origin for the System module.
-#[derive(PartialEq, Eq, Clone, RuntimeDebug, Encode, Decode)]
-pub enum RawOrigin<AccountId> {
-	/// The system itself ordained this dispatch to happen: this is the highest privilege level.
-	Root,
-	/// It is signed by some public key and we provide the `AccountId`.
-	Signed(AccountId),
-	/// It is signed by nobody, can be either:
-	/// * included and agreed upon by the validators anyway,
-	/// * or unsigned transaction validated by a module.
-	None,
-}
-
-impl<AccountId> From<Option<AccountId>> for RawOrigin<AccountId> {
-	fn from(s: Option<AccountId>) -> RawOrigin<AccountId> {
-		match s {
-			Some(who) => RawOrigin::Signed(who),
-			None => RawOrigin::None,
-		}
-	}
-}
-
-/// Exposed trait-generic origin type.
-pub type Origin<T> = RawOrigin<<T as Config>::AccountId>;
-
-// Create a Hash with 69 for each byte,
-// only used to build genesis config.
-#[cfg(feature = "std")]
-fn hash69<T: AsMut<[u8]> + Default>() -> T {
-	let mut h = T::default();
-	h.as_mut().iter_mut().for_each(|byte| *byte = 69);
-	h
-}
-
-/// This type alias represents an index of an event.
-///
-/// We use `u32` here because this index is used as index for `Events<T>`
-/// which can't contain more than `u32::max_value()` items.
-type EventIndex = u32;
-
-/// Type used to encode the number of references an account has.
-pub type RefCount = u32;
-
-/// Information of an account.
-#[derive(Clone, Eq, PartialEq, Default, RuntimeDebug, Encode, Decode)]
-pub struct AccountInfo<Index, AccountData> {
-	/// The number of transactions this account has sent.
-	pub nonce: Index,
-	/// The number of other modules that currently depend on this account's existence. The account
-	/// cannot be reaped until this is zero.
-	pub consumers: RefCount,
-	/// The number of other modules that allow this account to exist. The account may not be reaped
-	/// until this is zero.
-	pub providers: RefCount,
-	/// The additional data that belongs to this account. Used to store the balance(s) in a lot of
-	/// chains.
-	pub data: AccountData,
-}
-
-/// Stores the `spec_version` and `spec_name` of when the last runtime upgrade
-/// happened.
-#[derive(sp_runtime::RuntimeDebug, Encode, Decode)]
-#[cfg_attr(feature = "std", derive(PartialEq))]
-pub struct LastRuntimeUpgradeInfo {
-	pub spec_version: codec::Compact<u32>,
-	pub spec_name: sp_runtime::RuntimeString,
-}
-
-impl LastRuntimeUpgradeInfo {
-	/// Returns if the runtime was upgraded in comparison of `self` and `current`.
-	///
-	/// Checks if either the `spec_version` increased or the `spec_name` changed.
-	pub fn was_upgraded(&self, current: &sp_version::RuntimeVersion) -> bool {
-		current.spec_version > self.spec_version.0 || current.spec_name != self.spec_name
-	}
-}
-
-impl From<sp_version::RuntimeVersion> for LastRuntimeUpgradeInfo {
-	fn from(version: sp_version::RuntimeVersion) -> Self {
-		Self {
-			spec_version: version.spec_version.into(),
-			spec_name: version.spec_name,
-		}
-	}
-}
-
-decl_storage! {
-	trait Store for Module<T: Config> as System {
-		/// The full account information for a particular account ID.
-		pub Account get(fn account):
-			map hasher(blake2_128_concat) T::AccountId => AccountInfo<T::Index, T::AccountData>;
-
-		/// Total extrinsics count for the current block.
-		ExtrinsicCount: Option<u32>;
-
-		/// The current weight for the block.
-		BlockWeight get(fn block_weight): ConsumedWeight;
-
-		/// Total length (in bytes) for all extrinsics put together, for the current block.
-		AllExtrinsicsLen: Option<u32>;
-
-		/// Map of block numbers to block hashes.
-		pub BlockHash get(fn block_hash) build(|_| vec![(T::BlockNumber::zero(), hash69())]):
-			map hasher(twox_64_concat) T::BlockNumber => T::Hash;
-
-		/// Extrinsics data for the current block (maps an extrinsic's index to its data).
-		ExtrinsicData get(fn extrinsic_data): map hasher(twox_64_concat) u32 => Vec<u8>;
-
-		/// The current block number being processed. Set by `execute_block`.
-		Number get(fn block_number): T::BlockNumber;
+pub use pallet::*;
+
+#[frame_support::pallet]
+pub mod pallet {
+	use crate::{*, pallet_prelude::*, self as frame_system};
+	use frame_support::pallet_prelude::*;
+
+	/// System configuration trait. Implemented by runtime.
+	#[pallet::config]
+	#[pallet::disable_frame_system_supertrait_check]
+	pub trait Config: 'static + Eq + Clone {
+		/// The basic call filter to use in Origin. All origins are built with this filter as base,
+		/// except Root.
+		type BaseCallFilter: Filter<Self::Call>;
+
+		/// Block & extrinsics weights: base values and limits.
+		#[pallet::constant]
+		type BlockWeights: Get<limits::BlockWeights>;
+
+		/// The maximum length of a block (in bytes).
+		#[pallet::constant]
+		type BlockLength: Get<limits::BlockLength>;
+
+		/// The `Origin` type used by dispatchable calls.
+		type Origin:
+			Into<Result<RawOrigin<Self::AccountId>, Self::Origin>>
+			+ From<RawOrigin<Self::AccountId>>
+			+ Clone
+			+ OriginTrait<Call=Self::Call>;
+
+		/// The aggregated `Call` type.
+		type Call: Dispatchable + Debug;
+
+		/// Account index (aka nonce) type. This stores the number of previous transactions associated
+		/// with a sender account.
+		type Index:
+			Parameter + Member + MaybeSerialize + Debug + Default + MaybeDisplay + AtLeast32Bit
+			+ Copy;
+
+		/// The block number type used by the runtime.
+		type BlockNumber:
+			Parameter + Member + MaybeSerializeDeserialize + Debug + MaybeDisplay +
+			AtLeast32BitUnsigned + Default + Bounded + Copy + sp_std::hash::Hash +
+			sp_std::str::FromStr + MaybeMallocSizeOf;
+
+		/// The output of the `Hashing` function.
+		type Hash:
+			Parameter + Member + MaybeSerializeDeserialize + Debug + MaybeDisplay + SimpleBitOps + Ord
+			+ Default + Copy + CheckEqual + sp_std::hash::Hash + AsRef<[u8]> + AsMut<[u8]> + MaybeMallocSizeOf;
+
+		/// The hashing system (algorithm) being used in the runtime (e.g. Blake2).
+		type Hashing: Hash<Output=Self::Hash>;
+
+		/// The user account identifier type for the runtime.
+		type AccountId: Parameter + Member + MaybeSerializeDeserialize + Debug + MaybeDisplay + Ord
+			+ Default;
+
+		/// Converting trait to take a source type and convert to `AccountId`.
+		///
+		/// Used to define the type and conversion mechanism for referencing accounts in transactions.
+		/// It's perfectly reasonable for this to be an identity conversion (with the source type being
+		/// `AccountId`), but other pallets (e.g. Indices pallet) may provide more functional/efficient
+		/// alternatives.
+		type Lookup: StaticLookup<Target=Self::AccountId>;
 
-		/// Hash of the previous block.
-		ParentHash get(fn parent_hash) build(|_| hash69()): T::Hash;
+		/// The block header.
+		type Header: Parameter + traits::Header<
+			Number=Self::BlockNumber,
+			Hash=Self::Hash,
+		>;
 
-		/// Digest of the current block, also part of the block header.
-		Digest get(fn digest): DigestOf<T>;
+		/// The aggregated event type of the runtime.
+		type Event: Parameter + Member + From<Event<Self>> + Debug + IsType<<Self as frame_system::Config>::Event>;
 
-		/// Events deposited for the current block.
-		Events get(fn events): Vec<EventRecord<T::Event, T::Hash>>;
+		/// Maximum number of block number to block hash mappings to keep (oldest pruned first).
+		#[pallet::constant]
+		type BlockHashCount: Get<Self::BlockNumber>;
 
-		/// The number of events in the `Events<T>` list.
-		EventCount get(fn event_count): EventIndex;
+		/// The weight of runtime database operations the runtime can invoke.
+		#[pallet::constant]
+		type DbWeight: Get<RuntimeDbWeight>;
 
-		// TODO: https://github.com/paritytech/substrate/issues/2553
-		// Possibly, we can improve it by using something like:
-		// `Option<(BlockNumber, Vec<EventIndex>)>`, however in this case we won't be able to use
-		// `EventTopics::append`.
+		/// Get the chain's current version.
+		#[pallet::constant]
+		type Version: Get<RuntimeVersion>;
 
-		/// Mapping between a topic (represented by T::Hash) and a vector of indexes
-		/// of events in the `<Events<T>>` list.
+		/// Provides information about the pallet setup in the runtime.
 		///
-		/// All topic vectors have deterministic storage locations depending on the topic. This
-		/// allows light-clients to leverage the changes trie storage tracking mechanism and
-		/// in case of changes fetch the list of events of interest.
+		/// Expects the `PalletInfo` type that is being generated by `construct_runtime!` in the
+		/// runtime.
 		///
-		/// The value has the type `(T::BlockNumber, EventIndex)` because if we used only just
-		/// the `EventIndex` then in case if the topic has the same contents on the next block
-		/// no notification will be triggered thus the event might be lost.
-		EventTopics get(fn event_topics): map hasher(blake2_128_concat) T::Hash => Vec<(T::BlockNumber, EventIndex)>;
-
-		/// Stores the `spec_version` and `spec_name` of when the last runtime upgrade happened.
-		pub LastRuntimeUpgrade build(|_| Some(LastRuntimeUpgradeInfo::from(T::Version::get()))): Option<LastRuntimeUpgradeInfo>;
+		/// For tests it is okay to use `()` as type, however it will provide "useless" data.
+		type PalletInfo: PalletInfo;
 
-		/// True if we have upgraded so that `type RefCount` is `u32`. False (default) if not.
-		UpgradedToU32RefCount build(|_| true): bool;
+		/// Data to be associated with an account (other than nonce/transaction counter, which this
+		/// pallet does regardless).
+		type AccountData: Member + FullCodec + Clone + Default;
 
-		/// True if we have upgraded so that AccountInfo contains two types of `RefCount`. False
-		/// (default) if not.
-		UpgradedToDualRefCount build(|_| true): bool;
+		/// Handler for when a new account has just been created.
+		type OnNewAccount: OnNewAccount<Self::AccountId>;
 
-		/// The execution phase of the block.
-		ExecutionPhase: Option<Phase>;
-	}
-	add_extra_genesis {
-		config(changes_trie_config): Option<ChangesTrieConfiguration>;
-		#[serde(with = "sp_core::bytes")]
-		config(code): Vec<u8>;
-
-		build(|config: &GenesisConfig| {
-			use codec::Encode;
-
-			sp_io::storage::set(well_known_keys::CODE, &config.code);
-			sp_io::storage::set(well_known_keys::EXTRINSIC_INDEX, &0u32.encode());
-
-			if let Some(ref changes_trie_config) = config.changes_trie_config {
-				sp_io::storage::set(
-					well_known_keys::CHANGES_TRIE_CONFIG,
-					&changes_trie_config.encode(),
-				);
-			}
-		});
-	}
-}
-
-decl_event!(
-	/// Event for the System module.
-	pub enum Event<T> where AccountId = <T as Config>::AccountId {
-		/// An extrinsic completed successfully. \[info\]
-		ExtrinsicSuccess(DispatchInfo),
-		/// An extrinsic failed. \[error, info\]
-		ExtrinsicFailed(DispatchError, DispatchInfo),
-		/// `:code` was updated.
-		CodeUpdated,
-		/// A new \[account\] was created.
-		NewAccount(AccountId),
-		/// An \[account\] was reaped.
-		KilledAccount(AccountId),
-	}
-);
-
-decl_error! {
-	/// Error for the System module
-	pub enum Error for Module<T: Config> {
-		/// The name of specification does not match between the current runtime
-		/// and the new runtime.
-		InvalidSpecName,
-		/// The specification version is not allowed to decrease between the current runtime
-		/// and the new runtime.
-		SpecVersionNeedsToIncrease,
-		/// Failed to extract the runtime version from the new runtime.
+		/// A function that is invoked when an account has been determined to be dead.
 		///
-		/// Either calling `Core_version` or decoding `RuntimeVersion` failed.
-		FailedToExtractRuntimeVersion,
-		/// Suicide called when the account has non-default composite data.
-		NonDefaultComposite,
-		/// There is a non-zero reference count preventing the account from being purged.
-		NonZeroRefCount,
-	}
-}
-
-mod migrations {
-	use super::*;
-
-	#[allow(dead_code)]
-	pub fn migrate_all<T: Config>() -> frame_support::weights::Weight {
-		Account::<T>::translate::<(T::Index, u8, T::AccountData), _>(|_key, (nonce, rc, data)|
-			Some(AccountInfo { nonce, consumers: rc as RefCount, providers: 1, data })
-		);
-		T::BlockWeights::get().max_block
-	}
-
-	pub fn migrate_to_dual_ref_count<T: Config>() -> frame_support::weights::Weight {
-		Account::<T>::translate::<(T::Index, RefCount, T::AccountData), _>(|_key, (nonce, rc, data)|
-			Some(AccountInfo { nonce, consumers: rc as RefCount, providers: 1, data })
-		);
-		T::BlockWeights::get().max_block
-	}
-}
+		/// All resources should be cleaned up associated with the given account.
+		type OnKilledAccount: OnKilledAccount<Self::AccountId>;
 
-/// Pallet struct placeholder on which is implemented the pallet logic.
-///
-/// It is currently an alias for `Module` as old macros still generate/use old name.
-pub type Pallet<T> = Module<T>;
-
-decl_module! {
-	pub struct Module<T: Config> for enum Call where origin: T::Origin, system=self {
-		type Error = Error<T>;
-
-		/// The maximum number of blocks to allow in mortal eras.
-		const BlockHashCount: T::BlockNumber = T::BlockHashCount::get();
-
-		/// The weight of runtime database operations the runtime can invoke.
-		const DbWeight: RuntimeDbWeight = T::DbWeight::get();
-
-		/// The weight configuration (limits & base values) for each class of extrinsics and block.
-		const BlockWeights: limits::BlockWeights = T::BlockWeights::get();
+		type SystemWeightInfo: WeightInfo;
 
 		/// The designated SS85 prefix of this chain.
 		///
 		/// This replaces the "ss58Format" property declared in the chain spec. Reason is
 		/// that the runtime should know about the prefix in order to make use of it as
 		/// an identifier of the chain.
-		const SS58Prefix: u8 = T::SS58Prefix::get();
+		#[pallet::constant]
+		type SS58Prefix: Get<u8>;
+	}
 
+	#[pallet::pallet]
+	#[pallet::generate_store(pub (super) trait Store)]
+	pub struct Pallet<T>(PhantomData<T>);
+
+	#[pallet::hooks]
+	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
 		fn on_runtime_upgrade() -> frame_support::weights::Weight {
-			if !UpgradedToDualRefCount::get() {
-				UpgradedToDualRefCount::put(true);
+			if !UpgradedToDualRefCount::<T>::get() {
+				UpgradedToDualRefCount::<T>::put(true);
 				migrations::migrate_to_dual_ref_count::<T>()
 			} else {
 				0
@@ -568,13 +273,17 @@ decl_module! {
 				.validate()
 				.expect("The weights are invalid.");
 		}
+	}
 
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {
 		/// A dispatch that will fill the block weight up to the given ratio.
 		// TODO: This should only be available for testing, rather than in general usage, but
-		// that's not possible at present (since it's within the decl_module macro).
-		#[weight = *_ratio * T::BlockWeights::get().max_block]
-		fn fill_block(origin, _ratio: Perbill) {
+		// that's not possible at present (since it's within the pallet macro).
+		#[pallet::weight(*_ratio * T::BlockWeights::get().max_block)]
+		pub(crate) fn fill_block(origin: OriginFor<T>, _ratio: Perbill) -> DispatchResultWithPostInfo {
 			ensure_root(origin)?;
+			Ok(().into())
 		}
 
 		/// Make some on-chain remark.
@@ -584,9 +293,10 @@ decl_module! {
 		/// - Base Weight: 0.665 µs, independent of remark length.
 		/// - No DB operations.
 		/// # </weight>
-		#[weight = T::SystemWeightInfo::remark(_remark.len() as u32)]
-		fn remark(origin, _remark: Vec<u8>) {
+		#[pallet::weight(T::SystemWeightInfo::remark(_remark.len() as u32))]
+		pub(crate) fn remark(origin: OriginFor<T>, _remark: Vec<u8>) -> DispatchResultWithPostInfo {
 			ensure_signed(origin)?;
+			Ok(().into())
 		}
 
 		/// Set the number of pages in the WebAssembly environment's heap.
@@ -597,10 +307,11 @@ decl_module! {
 		/// - Base Weight: 1.405 µs
 		/// - 1 write to HEAP_PAGES
 		/// # </weight>
-		#[weight = (T::SystemWeightInfo::set_heap_pages(), DispatchClass::Operational)]
-		fn set_heap_pages(origin, pages: u64) {
+		#[pallet::weight((T::SystemWeightInfo::set_heap_pages(), DispatchClass::Operational))]
+		pub(crate) fn set_heap_pages(origin: OriginFor<T>, pages: u64) -> DispatchResultWithPostInfo {
 			ensure_root(origin)?;
 			storage::unhashed::put_raw(well_known_keys::HEAP_PAGES, &pages.encode());
+			Ok(().into())
 		}
 
 		/// Set the new runtime code.
@@ -613,13 +324,14 @@ decl_module! {
 		/// The weight of this function is dependent on the runtime, but generally this is very expensive.
 		/// We will treat this as a full block.
 		/// # </weight>
-		#[weight = (T::BlockWeights::get().max_block, DispatchClass::Operational)]
-		pub fn set_code(origin, code: Vec<u8>) {
+		#[pallet::weight((T::BlockWeights::get().max_block, DispatchClass::Operational))]
+		pub fn set_code(origin: OriginFor<T>, code: Vec<u8>) -> DispatchResultWithPostInfo {
 			ensure_root(origin)?;
 			Self::can_set_code(&code)?;
 
 			storage::unhashed::put_raw(well_known_keys::CODE, &code);
-			Self::deposit_event(RawEvent::CodeUpdated);
+			Self::deposit_event(Event::CodeUpdated);
+			Ok(().into())
 		}
 
 		/// Set the new runtime code without doing any checks of the given `code`.
@@ -630,11 +342,15 @@ decl_module! {
 		/// - 1 event.
 		/// The weight of this function is dependent on the runtime. We will treat this as a full block.
 		/// # </weight>
-		#[weight = (T::BlockWeights::get().max_block, DispatchClass::Operational)]
-		pub fn set_code_without_checks(origin, code: Vec<u8>) {
+		#[pallet::weight((T::BlockWeights::get().max_block, DispatchClass::Operational))]
+		pub fn set_code_without_checks(
+			origin: OriginFor<T>,
+			code: Vec<u8>,
+		) -> DispatchResultWithPostInfo {
 			ensure_root(origin)?;
 			storage::unhashed::put_raw(well_known_keys::CODE, &code);
-			Self::deposit_event(RawEvent::CodeUpdated);
+			Self::deposit_event(Event::CodeUpdated);
+			Ok(().into())
 		}
 
 		/// Set the new changes trie configuration.
@@ -647,8 +363,11 @@ decl_module! {
 		/// - DB Weight:
 		///     - Writes: Changes Trie, System Digest
 		/// # </weight>
-		#[weight = (T::SystemWeightInfo::set_changes_trie_config(), DispatchClass::Operational)]
-		pub fn set_changes_trie_config(origin, changes_trie_config: Option<ChangesTrieConfiguration>) {
+		#[pallet::weight((T::SystemWeightInfo::set_changes_trie_config(), DispatchClass::Operational))]
+		pub fn set_changes_trie_config(
+			origin: OriginFor<T>,
+			changes_trie_config: Option<ChangesTrieConfiguration>,
+		) -> DispatchResultWithPostInfo {
 			ensure_root(origin)?;
 			match changes_trie_config.clone() {
 				Some(changes_trie_config) => storage::unhashed::put_raw(
@@ -662,6 +381,7 @@ decl_module! {
 				generic::ChangesTrieSignal::NewConfiguration(changes_trie_config),
 			);
 			Self::deposit_log(log.into());
+			Ok(().into())
 		}
 
 		/// Set some items of storage.
@@ -672,15 +392,16 @@ decl_module! {
 		/// - Base Weight: 0.568 * i µs
 		/// - Writes: Number of items
 		/// # </weight>
-		#[weight = (
+		#[pallet::weight((
 			T::SystemWeightInfo::set_storage(items.len() as u32),
 			DispatchClass::Operational,
-		)]
-		fn set_storage(origin, items: Vec<KeyValue>) {
+		))]
+		pub(crate) fn set_storage(origin: OriginFor<T>, items: Vec<KeyValue>) -> DispatchResultWithPostInfo {
 			ensure_root(origin)?;
 			for i in &items {
 				storage::unhashed::put_raw(&i.0, &i.1);
 			}
+			Ok(().into())
 		}
 
 		/// Kill some items from storage.
@@ -691,15 +412,16 @@ decl_module! {
 		/// - Base Weight: .378 * i µs
 		/// - Writes: Number of items
 		/// # </weight>
-		#[weight = (
+		#[pallet::weight((
 			T::SystemWeightInfo::kill_storage(keys.len() as u32),
 			DispatchClass::Operational,
-		)]
-		fn kill_storage(origin, keys: Vec<Key>) {
+		))]
+		pub(crate) fn kill_storage(origin: OriginFor<T>, keys: Vec<Key>) -> DispatchResultWithPostInfo {
 			ensure_root(origin)?;
 			for key in &keys {
 				storage::unhashed::kill(&key);
 			}
+			Ok(().into())
 		}
 
 		/// Kill all storage items with a key that starts with the given prefix.
@@ -713,13 +435,347 @@ decl_module! {
 		/// - Base Weight: 0.834 * P µs
 		/// - Writes: Number of subkeys + 1
 		/// # </weight>
-		#[weight = (
+		#[pallet::weight((
 			T::SystemWeightInfo::kill_prefix(_subkeys.saturating_add(1)),
 			DispatchClass::Operational,
-		)]
-		fn kill_prefix(origin, prefix: Key, _subkeys: u32) {
+		))]
+		pub(crate) fn kill_prefix(
+			origin: OriginFor<T>,
+			prefix: Key,
+			_subkeys: u32,
+		) -> DispatchResultWithPostInfo {
 			ensure_root(origin)?;
 			storage::unhashed::kill_prefix(&prefix);
+			Ok(().into())
+		}
+	}
+
+	/// Event for the System pallet.
+	#[pallet::event]
+	#[pallet::metadata(T::AccountId = "AccountId")]
+	pub enum Event<T: Config> {
+		/// An extrinsic completed successfully. \[info\]
+		ExtrinsicSuccess(DispatchInfo),
+		/// An extrinsic failed. \[error, info\]
+		ExtrinsicFailed(DispatchError, DispatchInfo),
+		/// `:code` was updated.
+		CodeUpdated,
+		/// A new \[account\] was created.
+		NewAccount(T::AccountId),
+		/// An \[account\] was reaped.
+		KilledAccount(T::AccountId),
+	}
+
+	/// Old name generated by `decl_event`.
+	#[deprecated(note = "use `Event` instead")]
+	pub type RawEvent<T> = Event<T>;
+
+	/// Error for the System pallet
+	#[pallet::error]
+	pub enum Error<T> {
+		/// The name of specification does not match between the current runtime
+		/// and the new runtime.
+		InvalidSpecName,
+		/// The specification version is not allowed to decrease between the current runtime
+		/// and the new runtime.
+		SpecVersionNeedsToIncrease,
+		/// Failed to extract the runtime version from the new runtime.
+		///
+		/// Either calling `Core_version` or decoding `RuntimeVersion` failed.
+		FailedToExtractRuntimeVersion,
+		/// Suicide called when the account has non-default composite data.
+		NonDefaultComposite,
+		/// There is a non-zero reference count preventing the account from being purged.
+		NonZeroRefCount,
+	}
+
+	/// Exposed trait-generic origin type.
+	#[pallet::origin]
+	pub type Origin<T> = RawOrigin<<T as Config>::AccountId>;
+
+	/// The full account information for a particular account ID.
+	#[pallet::storage]
+	#[pallet::getter(fn account)]
+	pub type Account<T: Config> = StorageMap<
+		_,
+		Blake2_128Concat,
+		T::AccountId,
+		AccountInfo<T::Index, T::AccountData>,
+		ValueQuery,
+	>;
+
+	/// Total extrinsics count for the current block.
+	#[pallet::storage]
+	pub(super) type ExtrinsicCount<T: Config> = StorageValue<_, u32>;
+
+	/// The current weight for the block.
+	#[pallet::storage]
+	#[pallet::getter(fn block_weight)]
+	pub(super) type BlockWeight<T: Config> = StorageValue<_, ConsumedWeight, ValueQuery>;
+
+	/// Total length (in bytes) for all extrinsics put together, for the current block.
+	#[pallet::storage]
+	pub(super) type AllExtrinsicsLen<T: Config> = StorageValue<_, u32>;
+
+	/// Map of block numbers to block hashes.
+	#[pallet::storage]
+	#[pallet::getter(fn block_hash)]
+	pub type BlockHash<T: Config> =
+		StorageMap<_, Twox64Concat, T::BlockNumber, T::Hash, ValueQuery>;
+
+	/// Extrinsics data for the current block (maps an extrinsic's index to its data).
+	#[pallet::storage]
+	#[pallet::getter(fn extrinsic_data)]
+	pub(super) type ExtrinsicData<T: Config> =
+		StorageMap<_, Twox64Concat, u32, Vec<u8>, ValueQuery>;
+
+	/// The current block number being processed. Set by `execute_block`.
+	#[pallet::storage]
+	#[pallet::getter(fn block_number)]
+	pub(super) type Number<T: Config> = StorageValue<_, T::BlockNumber, ValueQuery>;
+
+	/// Hash of the previous block.
+	#[pallet::storage]
+	#[pallet::getter(fn parent_hash)]
+	pub(super) type ParentHash<T: Config> = StorageValue<_, T::Hash, ValueQuery>;
+
+	/// Digest of the current block, also part of the block header.
+	#[pallet::storage]
+	#[pallet::getter(fn digest)]
+	pub(super) type Digest<T: Config> = StorageValue<_, DigestOf<T>, ValueQuery>;
+
+	/// Events deposited for the current block.
+	#[pallet::storage]
+	#[pallet::getter(fn events)]
+	pub(super) type Events<T: Config> =
+		StorageValue<_, Vec<EventRecord<T::Event, T::Hash>>, ValueQuery>;
+
+	/// The number of events in the `Events<T>` list.
+	#[pallet::storage]
+	#[pallet::getter(fn event_count)]
+	pub(super) type EventCount<T: Config> = StorageValue<_, EventIndex, ValueQuery>;
+
+	/// Mapping between a topic (represented by T::Hash) and a vector of indexes
+	/// of events in the `<Events<T>>` list.
+	///
+	/// All topic vectors have deterministic storage locations depending on the topic. This
+	/// allows light-clients to leverage the changes trie storage tracking mechanism and
+	/// in case of changes fetch the list of events of interest.
+	///
+	/// The value has the type `(T::BlockNumber, EventIndex)` because if we used only just
+	/// the `EventIndex` then in case if the topic has the same contents on the next block
+	/// no notification will be triggered thus the event might be lost.
+	#[pallet::storage]
+	#[pallet::getter(fn event_topics)]
+	pub(super) type EventTopics<T: Config> =
+		StorageMap<_, Blake2_128Concat, T::Hash, Vec<(T::BlockNumber, EventIndex)>, ValueQuery>;
+
+	/// Stores the `spec_version` and `spec_name` of when the last runtime upgrade happened.
+	#[pallet::storage]
+	pub type LastRuntimeUpgrade<T: Config> = StorageValue<_, LastRuntimeUpgradeInfo>;
+
+	/// True if we have upgraded so that `type RefCount` is `u32`. False (default) if not.
+	#[pallet::storage]
+	pub(super) type UpgradedToU32RefCount<T: Config> = StorageValue<_, bool, ValueQuery>;
+
+	/// True if we have upgraded so that AccountInfo contains two types of `RefCount`. False
+	/// (default) if not.
+	#[pallet::storage]
+	pub(super) type UpgradedToDualRefCount<T: Config> = StorageValue<_, bool, ValueQuery>;
+
+	/// The execution phase of the block.
+	#[pallet::storage]
+	pub(super) type ExecutionPhase<T: Config> = StorageValue<_, Phase>;
+
+	#[pallet::genesis_config]
+	pub struct GenesisConfig {
+		pub changes_trie_config: Option<ChangesTrieConfiguration>,
+		#[serde(with = "sp_core::bytes")]
+		pub code: Vec<u8>,
+	}
+
+	#[cfg(feature = "std")]
+	impl Default for GenesisConfig {
+		fn default() -> Self {
+			Self {
+				changes_trie_config: Default::default(),
+				code: Default::default(),
+			}
+		}
+	}
+
+	#[pallet::genesis_build]
+	impl<T: Config> GenesisBuild<T> for GenesisConfig {
+		fn build(&self) {
+			<BlockHash<T>>::insert::<_, T::Hash>(T::BlockNumber::zero(), hash69());
+			<ParentHash<T>>::put::<T::Hash>(hash69());
+			<LastRuntimeUpgrade<T>>::put(LastRuntimeUpgradeInfo::from(T::Version::get()));
+			<UpgradedToU32RefCount<T>>::put(true);
+			<UpgradedToDualRefCount<T>>::put(true);
+
+			sp_io::storage::set(well_known_keys::CODE, &self.code);
+			sp_io::storage::set(well_known_keys::EXTRINSIC_INDEX, &0u32.encode());
+			if let Some(ref changes_trie_config) = self.changes_trie_config {
+				sp_io::storage::set(well_known_keys::CHANGES_TRIE_CONFIG, &changes_trie_config.encode());
+			}
+		}
+	}
+}
+
+mod migrations {
+	use super::*;
+
+	#[allow(dead_code)]
+	pub fn migrate_all<T: Config>() -> frame_support::weights::Weight {
+		Account::<T>::translate::<(T::Index, u8, T::AccountData), _>(|_key, (nonce, rc, data)|
+			Some(AccountInfo { nonce, consumers: rc as RefCount, providers: 1, data })
+		);
+		T::BlockWeights::get().max_block
+	}
+
+	pub fn migrate_to_dual_ref_count<T: Config>() -> frame_support::weights::Weight {
+		Account::<T>::translate::<(T::Index, RefCount, T::AccountData), _>(|_key, (nonce, rc, data)|
+			Some(AccountInfo { nonce, consumers: rc as RefCount, providers: 1, data })
+		);
+		T::BlockWeights::get().max_block
+	}
+}
+
+#[cfg(feature = "std")]
+impl GenesisConfig {
+	/// Direct implementation of `GenesisBuild::build_storage`.
+	///
+	/// Kept in order not to break dependency.
+	pub fn build_storage<T: Config>(&self) -> Result<sp_runtime::Storage, String> {
+		<Self as GenesisBuild<T>>::build_storage(self)
+	}
+
+	/// Direct implementation of `GenesisBuild::assimilate_storage`.
+	///
+	/// Kept in order not to break dependency.
+	pub fn assimilate_storage<T: Config>(
+		&self,
+		storage: &mut sp_runtime::Storage
+	) -> Result<(), String> {
+		<Self as GenesisBuild<T>>::assimilate_storage(self, storage)
+	}
+}
+
+pub type DigestOf<T> = generic::Digest<<T as Config>::Hash>;
+pub type DigestItemOf<T> = generic::DigestItem<<T as Config>::Hash>;
+
+pub type Key = Vec<u8>;
+pub type KeyValue = (Vec<u8>, Vec<u8>);
+
+/// A phase of a block's execution.
+#[derive(Encode, Decode, RuntimeDebug)]
+#[cfg_attr(feature = "std", derive(Serialize, PartialEq, Eq, Clone))]
+pub enum Phase {
+	/// Applying an extrinsic.
+	ApplyExtrinsic(u32),
+	/// Finalizing the block.
+	Finalization,
+	/// Initializing the block.
+	Initialization,
+}
+
+impl Default for Phase {
+	fn default() -> Self {
+		Self::Initialization
+	}
+}
+
+/// Record of an event happening.
+#[derive(Encode, Decode, RuntimeDebug)]
+#[cfg_attr(feature = "std", derive(Serialize, PartialEq, Eq, Clone))]
+pub struct EventRecord<E: Parameter + Member, T> {
+	/// The phase of the block it happened in.
+	pub phase: Phase,
+	/// The event itself.
+	pub event: E,
+	/// The list of the topics this event has.
+	pub topics: Vec<T>,
+}
+
+/// Origin for the System pallet.
+#[derive(PartialEq, Eq, Clone, RuntimeDebug, Encode, Decode)]
+pub enum RawOrigin<AccountId> {
+	/// The system itself ordained this dispatch to happen: this is the highest privilege level.
+	Root,
+	/// It is signed by some public key and we provide the `AccountId`.
+	Signed(AccountId),
+	/// It is signed by nobody, can be either:
+	/// * included and agreed upon by the validators anyway,
+	/// * or unsigned transaction validated by a pallet.
+	None,
+}
+
+impl<AccountId> From<Option<AccountId>> for RawOrigin<AccountId> {
+	fn from(s: Option<AccountId>) -> RawOrigin<AccountId> {
+		match s {
+			Some(who) => RawOrigin::Signed(who),
+			None => RawOrigin::None,
+		}
+	}
+}
+
+// Create a Hash with 69 for each byte,
+// only used to build genesis config.
+#[cfg(feature = "std")]
+fn hash69<T: AsMut<[u8]> + Default>() -> T {
+	let mut h = T::default();
+	h.as_mut().iter_mut().for_each(|byte| *byte = 69);
+	h
+}
+
+/// This type alias represents an index of an event.
+///
+/// We use `u32` here because this index is used as index for `Events<T>`
+/// which can't contain more than `u32::max_value()` items.
+type EventIndex = u32;
+
+/// Type used to encode the number of references an account has.
+pub type RefCount = u32;
+
+/// Information of an account.
+#[derive(Clone, Eq, PartialEq, Default, RuntimeDebug, Encode, Decode)]
+pub struct AccountInfo<Index, AccountData> {
+	/// The number of transactions this account has sent.
+	pub nonce: Index,
+	/// The number of other modules that currently depend on this account's existence. The account
+	/// cannot be reaped until this is zero.
+	pub consumers: RefCount,
+	/// The number of other modules that allow this account to exist. The account may not be reaped
+	/// until this is zero.
+	pub providers: RefCount,
+	/// The additional data that belongs to this account. Used to store the balance(s) in a lot of
+	/// chains.
+	pub data: AccountData,
+}
+
+/// Stores the `spec_version` and `spec_name` of when the last runtime upgrade
+/// happened.
+#[derive(sp_runtime::RuntimeDebug, Encode, Decode)]
+#[cfg_attr(feature = "std", derive(PartialEq))]
+pub struct LastRuntimeUpgradeInfo {
+	pub spec_version: codec::Compact<u32>,
+	pub spec_name: sp_runtime::RuntimeString,
+}
+
+impl LastRuntimeUpgradeInfo {
+	/// Returns if the runtime was upgraded in comparison of `self` and `current`.
+	///
+	/// Checks if either the `spec_version` increased or the `spec_name` changed.
+	pub fn was_upgraded(&self, current: &sp_version::RuntimeVersion) -> bool {
+		current.spec_version > self.spec_version.0 || current.spec_name != self.spec_name
+	}
+}
+
+impl From<sp_version::RuntimeVersion> for LastRuntimeUpgradeInfo {
+	fn from(version: sp_version::RuntimeVersion) -> Self {
+		Self {
+			spec_version: version.spec_version.into(),
+			spec_name: version.spec_name,
 		}
 	}
 }
@@ -1064,7 +1120,7 @@ impl<T: Config> Module<T> {
 		// Don't populate events on genesis.
 		if block_number.is_zero() { return }
 
-		let phase = ExecutionPhase::get().unwrap_or_default();
+		let phase = ExecutionPhase::<T>::get().unwrap_or_default();
 		let event = EventRecord {
 			phase,
 			event,
@@ -1073,14 +1129,14 @@ impl<T: Config> Module<T> {
 
 		// Index of the to be added event.
 		let event_idx = {
-			let old_event_count = EventCount::get();
+			let old_event_count = EventCount::<T>::get();
 			let new_event_count = match old_event_count.checked_add(1) {
 				// We've reached the maximum number of events at this block, just
 				// don't do anything and leave the event_count unaltered.
 				None => return,
 				Some(nc) => nc,
 			};
-			EventCount::put(new_event_count);
+			EventCount::<T>::put(new_event_count);
 			old_event_count
 		};
 
@@ -1098,17 +1154,17 @@ impl<T: Config> Module<T> {
 
 	/// Gets extrinsics count.
 	pub fn extrinsic_count() -> u32 {
-		ExtrinsicCount::get().unwrap_or_default()
+		ExtrinsicCount::<T>::get().unwrap_or_default()
 	}
 
 	pub fn all_extrinsics_len() -> u32 {
-		AllExtrinsicsLen::get().unwrap_or_default()
+		AllExtrinsicsLen::<T>::get().unwrap_or_default()
 	}
 
-	/// Inform the system module of some additional weight that should be accounted for, in the
+	/// Inform the system pallet of some additional weight that should be accounted for, in the
 	/// current block.
 	///
-	/// NOTE: use with extra care; this function is made public only be used for certain modules
+	/// NOTE: use with extra care; this function is made public only be used for certain pallets
 	/// that need it. A runtime that does not have dynamic calls should never need this and should
 	/// stick to static weights. A typical use case for this is inner calls or smart contract calls.
 	/// Furthermore, it only makes sense to use this when it is presumably  _cheap_ to provide the
@@ -1121,7 +1177,7 @@ impl<T: Config> Module<T> {
 	///
 	/// Another potential use-case could be for the `on_initialize` and `on_finalize` hooks.
 	pub fn register_extra_weight_unchecked(weight: Weight, class: DispatchClass) {
-		BlockWeight::mutate(|current_weight| {
+		BlockWeight::<T>::mutate(|current_weight| {
 			current_weight.add(weight, class);
 		});
 	}
@@ -1134,7 +1190,7 @@ impl<T: Config> Module<T> {
 		kind: InitKind,
 	) {
 		// populate environment
-		ExecutionPhase::put(Phase::Initialization);
+		ExecutionPhase::<T>::put(Phase::Initialization);
 		storage::unhashed::put(well_known_keys::EXTRINSIC_INDEX, &0u32);
 		<Number<T>>::put(number);
 		<Digest<T>>::put(digest);
@@ -1142,12 +1198,12 @@ impl<T: Config> Module<T> {
 		<BlockHash<T>>::insert(*number - One::one(), parent_hash);
 
 		// Remove previous block data from storage
-		BlockWeight::kill();
+		BlockWeight::<T>::kill();
 
 		// Kill inspectable storage entries in state when `InitKind::Full`.
 		if let InitKind::Full = kind {
 			<Events<T>>::kill();
-			EventCount::kill();
+			EventCount::<T>::kill();
 			<EventTopics<T>>::remove_all();
 		}
 	}
@@ -1155,8 +1211,8 @@ impl<T: Config> Module<T> {
 	/// Remove temporary "environment" entries in storage, compute the storage root and return the
 	/// resulting header for this block.
 	pub fn finalize() -> T::Header {
-		ExecutionPhase::kill();
-		AllExtrinsicsLen::kill();
+		ExecutionPhase::<T>::kill();
+		AllExtrinsicsLen::<T>::kill();
 
 		// The following fields
 		//
@@ -1172,8 +1228,8 @@ impl<T: Config> Module<T> {
 		let parent_hash = <ParentHash<T>>::get();
 		let mut digest = <Digest<T>>::get();
 
-		let extrinsics = (0..ExtrinsicCount::take().unwrap_or_default())
-			.map(ExtrinsicData::take)
+		let extrinsics = (0..ExtrinsicCount::<T>::take().unwrap_or_default())
+			.map(ExtrinsicData::<T>::take)
 			.collect();
 		let extrinsics_root = extrinsics_data_root::<T::Hashing>(extrinsics);
 
@@ -1213,7 +1269,7 @@ impl<T: Config> Module<T> {
 		<Digest<T>>::append(item);
 	}
 
-	/// Get the basic externalities for this module, useful for tests.
+	/// Get the basic externalities for this pallet, useful for tests.
 	#[cfg(any(feature = "std", test))]
 	pub fn externalities() -> TestExternalities {
 		TestExternalities::new(sp_core::storage::Storage {
@@ -1249,10 +1305,10 @@ impl<T: Config> Module<T> {
 	/// Set the current block weight. This should only be used in some integration tests.
 	#[cfg(any(feature = "std", test))]
 	pub fn set_block_consumed_resources(weight: Weight, len: usize) {
-		BlockWeight::mutate(|current_weight| {
+		BlockWeight::<T>::mutate(|current_weight| {
 			current_weight.set(weight, DispatchClass::Normal)
 		});
-		AllExtrinsicsLen::put(len as u32);
+		AllExtrinsicsLen::<T>::put(len as u32);
 	}
 
 	/// Reset events. Can be used as an alternative to
@@ -1260,7 +1316,7 @@ impl<T: Config> Module<T> {
 	#[cfg(any(feature = "std", feature = "runtime-benchmarks", test))]
 	pub fn reset_events() {
 		<Events<T>>::kill();
-		EventCount::kill();
+		EventCount::<T>::kill();
 		<EventTopics<T>>::remove_all();
 	}
 
@@ -1282,7 +1338,7 @@ impl<T: Config> Module<T> {
 	/// This is required to be called before applying an extrinsic. The data will used
 	/// in [`Self::finalize`] to calculate the correct extrinsics root.
 	pub fn note_extrinsic(encoded_xt: Vec<u8>) {
-		ExtrinsicData::insert(Self::extrinsic_index().unwrap_or_default(), encoded_xt);
+		ExtrinsicData::<T>::insert(Self::extrinsic_index().unwrap_or_default(), encoded_xt);
 	}
 
 	/// To be called immediately after an extrinsic has been applied.
@@ -1290,10 +1346,10 @@ impl<T: Config> Module<T> {
 		info.weight = extract_actual_weight(r, &info);
 		Self::deposit_event(
 			match r {
-				Ok(_) => RawEvent::ExtrinsicSuccess(info),
+				Ok(_) => Event::ExtrinsicSuccess(info),
 				Err(err) => {
 					sp_runtime::print(err);
-					RawEvent::ExtrinsicFailed(err.error, info)
+					Event::ExtrinsicFailed(err.error, info)
 				},
 			}
 		);
@@ -1301,7 +1357,7 @@ impl<T: Config> Module<T> {
 		let next_extrinsic_index = Self::extrinsic_index().unwrap_or_default() + 1u32;
 
 		storage::unhashed::put(well_known_keys::EXTRINSIC_INDEX, &next_extrinsic_index);
-		ExecutionPhase::put(Phase::ApplyExtrinsic(next_extrinsic_index));
+		ExecutionPhase::<T>::put(Phase::ApplyExtrinsic(next_extrinsic_index));
 	}
 
 	/// To be called immediately after `note_applied_extrinsic` of the last extrinsic of the block
@@ -1309,26 +1365,26 @@ impl<T: Config> Module<T> {
 	pub fn note_finished_extrinsics() {
 		let extrinsic_index: u32 = storage::unhashed::take(well_known_keys::EXTRINSIC_INDEX)
 			.unwrap_or_default();
-		ExtrinsicCount::put(extrinsic_index);
-		ExecutionPhase::put(Phase::Finalization);
+		ExtrinsicCount::<T>::put(extrinsic_index);
+		ExecutionPhase::<T>::put(Phase::Finalization);
 	}
 
 	/// To be called immediately after finishing the initialization of the block
-	/// (e.g., called `on_initialize` for all modules).
+	/// (e.g., called `on_initialize` for all pallets).
 	pub fn note_finished_initialize() {
-		ExecutionPhase::put(Phase::ApplyExtrinsic(0))
+		ExecutionPhase::<T>::put(Phase::ApplyExtrinsic(0))
 	}
 
 	/// An account is being created.
 	pub fn on_created_account(who: T::AccountId, _a: &mut AccountInfo<T::Index, T::AccountData>) {
 		T::OnNewAccount::on_new_account(&who);
-		Self::deposit_event(RawEvent::NewAccount(who));
+		Self::deposit_event(Event::NewAccount(who));
 	}
 
 	/// Do anything that needs to be done after an account has been killed.
 	fn on_killed_account(who: T::AccountId) {
 		T::OnKilledAccount::on_killed_account(&who);
-		Self::deposit_event(RawEvent::KilledAccount(who));
+		Self::deposit_event(Event::KilledAccount(who));
 	}
 
 	/// Determine whether or not it is possible to update the code.
@@ -1385,12 +1441,12 @@ impl<T: Config> HandleLifetime<T::AccountId> for Consumer<T> {
 	}
 }
 
-impl<T: Config> BlockNumberProvider for Module<T>
+impl<T: Config> BlockNumberProvider for Pallet<T>
 {
 	type BlockNumber = <T as Config>::BlockNumber;
 
 	fn current_block_number() -> Self::BlockNumber {
-		Module::<T>::block_number()
+		Pallet::<T>::block_number()
 	}
 }
 
@@ -1403,7 +1459,7 @@ fn is_providing<T: Default + Eq>(d: &T) -> bool {
 /// empty/default.
 ///
 /// Anything more complex will need more sophisticated logic.
-impl<T: Config> StoredMap<T::AccountId, T::AccountData> for Module<T> {
+impl<T: Config> StoredMap<T::AccountId, T::AccountData> for Pallet<T> {
 	fn get(k: &T::AccountId) -> T::AccountData {
 		Account::<T>::get(k).data
 	}
diff --git a/substrate/frame/system/src/limits.rs b/substrate/frame/system/src/limits.rs
index 3d59bd2b7fa22399b3a4c4ab304917f810e15304..c24d671cdd7abe1028bbf5d0ea8ee01c35905f3d 100644
--- a/substrate/frame/system/src/limits.rs
+++ b/substrate/frame/system/src/limits.rs
@@ -29,7 +29,7 @@ use frame_support::weights::{Weight, DispatchClass, constants, PerDispatchClass,
 use sp_runtime::{RuntimeDebug, Perbill};
 
 /// Block length limit configuration.
-#[derive(RuntimeDebug, Clone)]
+#[derive(RuntimeDebug, Clone, codec::Encode, codec::Decode)]
 pub struct BlockLength {
 	/// Maximal total length in bytes for each extrinsic class.
 	///
diff --git a/substrate/frame/system/src/offchain.rs b/substrate/frame/system/src/offchain.rs
index db417c028675dec812991993bfbaacf7c1c37210..05a5882ee3982364654a7f8491ef9fca81b9795d 100644
--- a/substrate/frame/system/src/offchain.rs
+++ b/substrate/frame/system/src/offchain.rs
@@ -63,7 +63,7 @@ use sp_std::convert::{TryInto, TryFrom};
 use sp_std::prelude::{Box, Vec};
 use sp_runtime::app_crypto::RuntimeAppPublic;
 use sp_runtime::traits::{Extrinsic as ExtrinsicT, IdentifyAccount, One};
-use frame_support::{debug, storage::StorageMap, RuntimeDebug};
+use frame_support::{debug, RuntimeDebug};
 
 /// Marker struct used to flag using all supported keys to sign a payload.
 pub struct ForAll {}
diff --git a/substrate/frame/system/src/tests.rs b/substrate/frame/system/src/tests.rs
index 89b84a2cc7ed5cb462220107d94f34a0e998f9be..d1992a14e06aa1c7214d39b7cafc2293a30afb36 100644
--- a/substrate/frame/system/src/tests.rs
+++ b/substrate/frame/system/src/tests.rs
@@ -18,8 +18,11 @@
 use crate::*;
 use mock::{*, Origin};
 use sp_core::H256;
-use sp_runtime::{DispatchError, traits::{Header, BlakeTwo256}};
-use frame_support::weights::WithPostDispatchInfo;
+use sp_runtime::{DispatchError, DispatchErrorWithPostInfo, traits::{Header, BlakeTwo256}};
+use frame_support::{
+	weights::WithPostDispatchInfo,
+	dispatch::PostDispatchInfo,
+};
 
 #[test]
 fn origin_works() {
@@ -329,7 +332,7 @@ fn set_code_checks_works() {
 		("test", 1, 2, Err(Error::<Test>::SpecVersionNeedsToIncrease)),
 		("test", 1, 1, Err(Error::<Test>::SpecVersionNeedsToIncrease)),
 		("test2", 1, 1, Err(Error::<Test>::InvalidSpecName)),
-		("test", 2, 1, Ok(())),
+		("test", 2, 1, Ok(PostDispatchInfo::default())),
 		("test", 0, 1, Err(Error::<Test>::SpecVersionNeedsToIncrease)),
 		("test", 1, 0, Err(Error::<Test>::SpecVersionNeedsToIncrease)),
 	];
@@ -351,7 +354,7 @@ fn set_code_checks_works() {
 				vec![1, 2, 3, 4],
 			);
 
-			assert_eq!(expected.map_err(DispatchError::from), res);
+			assert_eq!(expected.map_err(DispatchErrorWithPostInfo::from), res);
 		});
 	}
 }
diff --git a/substrate/frame/transaction-payment/src/lib.rs b/substrate/frame/transaction-payment/src/lib.rs
index c55eb333237cce5f55dfc2882cc9d3d442e02734..7521fcd80bf0a9ebd1b2f280822ff73b32afa5cc 100644
--- a/substrate/frame/transaction-payment/src/lib.rs
+++ b/substrate/frame/transaction-payment/src/lib.rs
@@ -1169,7 +1169,7 @@ mod tests {
 			}));
 			// Killed Event
 			assert!(System::events().iter().any(|event| {
-				event.event == Event::system(system::RawEvent::KilledAccount(2))
+				event.event == Event::system(system::Event::KilledAccount(2))
 			}));
 		});
 	}