diff --git a/beacon_chain/attestation_pool.nim b/beacon_chain/attestation_pool.nim
index 823206609..5764e7dbc 100644
--- a/beacon_chain/attestation_pool.nim
+++ b/beacon_chain/attestation_pool.nim
@@ -97,8 +97,8 @@ proc validate(
             data: attestation.data, custody_bit: true)),
         ],
         attestation.aggregate_signature,
-        get_domain(state.fork, slot_to_epoch(attestation.data.slot),
-                  DOMAIN_ATTESTATION),
+        get_domain(state, DOMAIN_ATTESTATION,
+                   slot_to_epoch(attestation.data.slot)),
       ):
       notice "Invalid signature", participants
       return false
diff --git a/beacon_chain/beacon_node.nim b/beacon_chain/beacon_node.nim
index 86cd540c2..a5fb89d1b 100644
--- a/beacon_chain/beacon_node.nim
+++ b/beacon_chain/beacon_node.nim
@@ -380,7 +380,7 @@ proc proposeBlock(node: BeaconNode,
 
     # Careful, state no longer valid after here..
     newBlock.signature =
-      await validator.signBlockProposal(state.fork, slot, blockRoot)
+      await validator.signBlockProposal(state, slot, blockRoot)
 
     (blockRoot, newBlock)
 
diff --git a/beacon_chain/spec/beaconstate.nim b/beacon_chain/spec/beaconstate.nim
index 6f9d8d260..a7a16aa7f 100644
--- a/beacon_chain/spec/beaconstate.nim
+++ b/beacon_chain/spec/beaconstate.nim
@@ -15,9 +15,9 @@ import
 func get_effective_balance*(state: BeaconState, index: ValidatorIndex): Gwei =
   ## Return the effective balance (also known as "balance at stake") for a
   ## validator with the given ``index``.
-  min(state.validator_balances[index], MAX_DEPOSIT_AMOUNT)
+  min(state.balances[index], MAX_EFFECTIVE_BALANCE)
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#verify_merkle_branch
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#verify_merkle_branch
 func verify_merkle_branch(leaf: Eth2Digest, proof: openarray[Eth2Digest], depth: uint64, index: uint64, root: Eth2Digest): bool =
   ## Verify that the given ``leaf`` is on the merkle branch ``proof``
   ## starting with the given ``root``.
@@ -106,7 +106,7 @@ func process_deposit*(state: var BeaconState, deposit: Deposit): bool =
     ## Note: In phase 2 registry indices that have been withdrawn for a long
     ## time will be recycled.
     state.validator_registry.add(validator)
-    state.validator_balances.add(amount)
+    state.balances.add(amount)
   else:
     # Increase balance by deposit amount
     let index = validator_pubkeys.find(pubkey)
@@ -114,11 +114,11 @@ func process_deposit*(state: var BeaconState, deposit: Deposit): bool =
     doAssert state.validator_registry[index].withdrawal_credentials ==
       withdrawal_credentials
 
-    state.validator_balances[index] += amount
+    state.balances[index] += amount
 
   true
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#get_delayed_activation_exit_epoch
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#get_delayed_activation_exit_epoch
 func get_delayed_activation_exit_epoch*(epoch: Epoch): Epoch =
   ## Return the epoch at which an activation or exit triggered in ``epoch``
   ## takes effect.
@@ -189,8 +189,8 @@ func slash_validator*(state: var BeaconState, index: ValidatorIndex) =
   ## TODO here and elsewhere, if reduce_balance can't reduce balance by full
   ## whistleblower_reward (to prevent underflow) should increase be full? It
   ## seems wrong for the amounts to differ.
-  state.validator_balances[whistleblower_index] += whistleblower_reward
-  reduce_balance(state.validator_balances[index], whistleblower_reward)
+  state.balances[whistleblower_index] += whistleblower_reward
+  reduce_balance(state.balances[index], whistleblower_reward)
   validator.slashed = true
   validator.withdrawable_epoch =
     get_current_epoch(state) + LATEST_SLASHED_EXIT_LENGTH
@@ -246,7 +246,7 @@ func get_genesis_beacon_state*(
 
     validator_registry_update_epoch: GENESIS_EPOCH,
 
-    # validator_registry and validator_balances automatically initalized
+    # validator_registry and balances automatically initalized
 
     # Randomness and committees
     # latest_randao_mixes automatically initialized
@@ -289,7 +289,7 @@ func get_genesis_beacon_state*(
   # Process genesis activations
   for validator_index in 0 ..< state.validator_registry.len:
     let vi = validator_index.ValidatorIndex
-    if get_effective_balance(state, vi) >= MAX_DEPOSIT_AMOUNT:
+    if get_effective_balance(state, vi) >= MAX_EFFECTIVE_BALANCE:
       activate_validator(state, vi, true)
 
   let genesis_active_index_root = hash_tree_root(
@@ -400,7 +400,7 @@ func process_ejections*(state: var BeaconState) =
   ## balance below ``EJECTION_BALANCE``
   for index in get_active_validator_indices(
       state.validator_registry, get_current_epoch(state)):
-    if state.validator_balances[index] < EJECTION_BALANCE:
+    if state.balances[index] < EJECTION_BALANCE:
       exit_validator(state, index)
 
 # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#get_total_balance
@@ -432,7 +432,7 @@ func update_validator_registry*(state: var BeaconState) =
 
     # The maximum balance churn in Gwei (for deposits and exits separately)
     max_balance_churn = max(
-        MAX_DEPOSIT_AMOUNT,
+        MAX_EFFECTIVE_BALANCE,
         total_balance div (2 * MAX_BALANCE_CHURN_QUOTIENT)
     )
 
@@ -440,7 +440,7 @@ func update_validator_registry*(state: var BeaconState) =
   var balance_churn = 0'u64
   for index, validator in state.validator_registry:
     if validator.activation_epoch == FAR_FUTURE_EPOCH and
-      state.validator_balances[index] >= MAX_DEPOSIT_AMOUNT:
+      state.balances[index] >= MAX_EFFECTIVE_BALANCE:
       # Check the balance churn would be within the allowance
       balance_churn += get_effective_balance(state, index.ValidatorIndex)
       if balance_churn > max_balance_churn:
@@ -600,8 +600,8 @@ proc checkAttestation*(
           data: attestation.data, custody_bit: true)),
       ],
       attestation.aggregate_signature,
-      get_domain(state.fork, slot_to_epoch(attestation.data.slot),
-                 DOMAIN_ATTESTATION),
+      get_domain(state, DOMAIN_ATTESTATION,
+                 slot_to_epoch(attestation.data.slot))
     ):
       warn("Invalid attestation signature")
       return
@@ -622,6 +622,22 @@ func prepare_validator_for_withdrawal*(state: var BeaconState, index: ValidatorI
   validator.withdrawable_epoch = get_current_epoch(state) +
     MIN_VALIDATOR_WITHDRAWABILITY_DELAY
 
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#increase_balance
+func increase_balance*(
+    state: var BeaconState, index: ValidatorIndex, delta: Gwei) =
+  # Increase validator balance by ``delta``.
+  state.balances[index] += delta
+
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#decrease_balance
+func decrease_balance*(
+    state: var BeaconState, index: ValidatorIndex, delta: Gwei) =
+  # Decrease validator balance by ``delta`` with underflow protection.
+  state.balances[index] =
+    if delta > state.balances[index]:
+      0'u64
+    else:
+      state.balances[index] - delta
+
 proc makeAttestationData*(
     state: BeaconState, shard: uint64,
     beacon_block_root: Eth2Digest): AttestationData =
diff --git a/beacon_chain/spec/bitfield.nim b/beacon_chain/spec/bitfield.nim
index 9d66de824..f6296f80b 100644
--- a/beacon_chain/spec/bitfield.nim
+++ b/beacon_chain/spec/bitfield.nim
@@ -16,14 +16,14 @@ func init*(T: type BitField, bits: int): BitField =
 proc readValue*(r: var JsonReader, a: var BitField) {.inline.} =
   a.bits = r.readValue(string).hexToSeqByte()
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#get_bitfield_bit
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#get_bitfield_bit
 func get_bitfield_bit*(bitfield: BitField, i: int): bool =
   # Extract the bit in ``bitfield`` at position ``i``.
   doAssert 0 <= i div 8, "i: " & $i & " i div 8: " & $(i div 8)
   doAssert i div 8 < bitfield.bits.len, "i: " & $i & " i div 8: " & $(i div 8)
   ((bitfield.bits[i div 8] shr (i mod 8)) mod 2) > 0'u8
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#verify_bitfield
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#verify_bitfield
 func verify_bitfield*(bitfield: BitField, committee_size: int): bool =
   # Verify ``bitfield`` against the ``committee_size``.
   if len(bitfield.bits) != (committee_size + 7) div 8:
diff --git a/beacon_chain/spec/crypto.nim b/beacon_chain/spec/crypto.nim
index 92e0ff911..ba994a77b 100644
--- a/beacon_chain/spec/crypto.nim
+++ b/beacon_chain/spec/crypto.nim
@@ -69,7 +69,7 @@ template hash*(k: ValidatorPubKey|ValidatorPrivKey): Hash =
 
 func pubKey*(pk: ValidatorPrivKey): ValidatorPubKey = pk.getKey()
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/bls_signature.md#bls_aggregate_pubkeys
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/bls_signature.md#bls_aggregate_pubkeys
 func bls_aggregate_pubkeys*(keys: openArray[ValidatorPubKey]): ValidatorPubKey =
   var empty = true
   for key in keys:
@@ -79,14 +79,14 @@ func bls_aggregate_pubkeys*(keys: openArray[ValidatorPubKey]): ValidatorPubKey =
     else:
       result.combine(key)
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/bls_signature.md#bls_verify
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/bls_signature.md#bls_verify
 func bls_verify*(
     pubkey: ValidatorPubKey, msg: openArray[byte], sig: ValidatorSig,
     domain: uint64): bool =
   # name from spec!
   sig.verify(msg, domain, pubkey)
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/bls_signature.md#bls_verify_multiple
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/bls_signature.md#bls_verify_multiple
 func bls_verify_multiple*(
     pubkeys: seq[ValidatorPubKey], message_hashes: openArray[Eth2Digest],
     sig: ValidatorSig, domain: uint64): bool =
diff --git a/beacon_chain/spec/datatypes.nim b/beacon_chain/spec/datatypes.nim
index 015a2622c..285d1fa99 100644
--- a/beacon_chain/spec/datatypes.nim
+++ b/beacon_chain/spec/datatypes.nim
@@ -68,19 +68,22 @@ const
   ## with a Verifiable Delay Function (VDF) will improve committee robustness
   ## and lower the safe minimum committee size.)
 
+  # TODO remove, not in post-0.5.1
   MAX_BALANCE_CHURN_QUOTIENT* = 2^5 ##\
-  ## At most `1/MAX_BALANCE_CHURN_QUOTIENT` of the validators can change during
-  ## each validator registry change.
 
-  MAX_INDICES_PER_SLASHABLE_VOTE* = 2^12 ##\
+  MAX_INDICES_PER_ATTESTATION* = 2^12 ##\
   ## votes
 
-  MAX_EXIT_DEQUEUES_PER_EPOCH* = 4
+  MIN_PER_EPOCH_CHURN_LIMIT* = 4
+
+  CHURN_LIMIT_QUOTIENT* = 2^16
+
+  BASE_REWARDS_PER_EPOCH* = 5
 
   SHUFFLE_ROUND_COUNT* = 90
 
   # Deposit contract
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#deposit-contract
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#deposit-contract
   DEPOSIT_CONTRACT_TREE_DEPTH* = 32
 
   # Gwei values
@@ -88,7 +91,7 @@ const
   MIN_DEPOSIT_AMOUNT* = 2'u64^0 * 10'u64^9 ##\
   ## Minimum amounth of ETH that can be deposited in one call - deposits can
   ## be used either to top up an existing validator or commit to a new one
-  MAX_DEPOSIT_AMOUNT* = 2'u64^5 * 10'u64^9 ##\
+  MAX_EFFECTIVE_BALANCE* = 2'u64^5 * 10'u64^9 ##\
   ## Maximum amounth of ETH that can be deposited in one call
 
   FORK_CHOICE_BALANCE_INCREMENT* = 2'u64^0 * 10'u64^9
@@ -141,8 +144,8 @@ const
   ACTIVATION_EXIT_DELAY* = 4 ##\
   ## epochs (~25.6 minutes)
 
-  EPOCHS_PER_ETH1_VOTING_PERIOD* = 2'u64^4 ##\
-  ## epochs (~1.7 hours)
+  SLOTS_PER_ETH1_VOTING_PERIOD* = 1024 ##\
+  ## slots (~1.7 hours)
 
   SLOTS_PER_HISTORICAL_ROOT* = 8192 ##\
   ## slots (13 hours)
@@ -153,28 +156,25 @@ const
   PERSISTENT_COMMITTEE_PERIOD* = 2'u64^11 ##\
   ## epochs (9 days)
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#state-list-lengths
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#state-list-lengths
   LATEST_RANDAO_MIXES_LENGTH* = 8192
   LATEST_ACTIVE_INDEX_ROOTS_LENGTH* = 8192 # 2'u64^13, epochs
   LATEST_SLASHED_EXIT_LENGTH* = 8192 # epochs
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#reward-and-penalty-quotients
-  BASE_REWARD_QUOTIENT* = 2'u64^5 ##\
-  ## The `BASE_REWARD_QUOTIENT` parameter dictates the per-epoch reward. It
-  ## corresponds to ~2.54% annual interest assuming 10 million participating
-  ## ETH in every epoch.
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#reward-and-penalty-quotients
+  BASE_REWARD_QUOTIENT* = 2'u64^5
   WHISTLEBLOWER_REWARD_QUOTIENT* = 2'u64^9
-  ATTESTATION_INCLUSION_REWARD_QUOTIENT* = 2'u64^3
-  INACTIVITY_PENALTY_QUOTIENT* = 2'u64^24
+  PROPOSER_REWARD_QUOTIENT* = 2'u64^3
+  INACTIVITY_PENALTY_QUOTIENT* = 2'u64^25
   MIN_PENALTY_QUOTIENT* = 32 # 2^5
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#max-transactions-per-block
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#max-operations-per-block
   MAX_PROPOSER_SLASHINGS* = 2^4
   MAX_ATTESTER_SLASHINGS* = 2^0
   MAX_ATTESTATIONS* = 2^7
   MAX_DEPOSITS* = 2^4
   MAX_VOLUNTARY_EXITS* = 2^4
-  MAX_TRANSFERS* = 2^4
+  MAX_TRANSFERS* = 0
 
 type
   ValidatorIndex* = range[0'u32 .. 0xFFFFFF'u32] # TODO: wrap-around
@@ -182,7 +182,7 @@ type
   Shard* = uint64
   Gwei* = uint64
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#proposerslashing
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#proposerslashing
   ProposerSlashing* = object
     proposer_index*: uint64 ##\
     ## Proposer index
@@ -193,15 +193,15 @@ type
     header_2*: BeaconBlockHeader ##\
     # Second block header
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#attesterslashing
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#attesterslashing
   AttesterSlashing* = object
-    slashable_attestation_1*: SlashableAttestation ## \
-    ## First slashable attestation
-    slashable_attestation_2*: SlashableAttestation ## \
-    ## Second slashable attestation
+    attestation_1*: IndexedAttestation ## \
+    ## First attestation
+    attestation_2*: IndexedAttestation ## \
+    ## Second attestation
 
   # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#slashableattestation
-  SlashableAttestation* = object
+  IndexedAttestation* = object
     validator_indices*: seq[uint64] ##\
     ## Validator indices
 
@@ -214,7 +214,7 @@ type
     aggregate_signature*: ValidatorSig ## \
     ## Aggregate signature
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#attestation
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#attestation
   Attestation* = object
     aggregation_bitfield*: BitField ##\
     ## Attester aggregation bitfield
@@ -244,7 +244,7 @@ type
     previous_crosslink*: Crosslink
     crosslink_data_root*: Eth2Digest
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#attestationdataandcustodybit
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#attestationdataandcustodybit
   AttestationDataAndCustodyBit* = object
     data*: AttestationData
     custody_bit*: bool
@@ -273,7 +273,7 @@ type
     proof_of_possession*: ValidatorSig ##\
     ## A BLS signature of this `DepositInput`
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#voluntaryexit
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#voluntaryexit
   VoluntaryExit* = object
     # Minimum epoch for processing exit
     epoch*: Epoch
@@ -282,7 +282,7 @@ type
     # Validator signature
     signature*: ValidatorSig
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#transfer
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#transfer
   Transfer* = object
     sender*: uint64 ##\
     ## Sender index
@@ -369,7 +369,7 @@ type
 
     # Validator registry
     validator_registry*: seq[Validator]
-    validator_balances*: seq[uint64] ##\
+    balances*: seq[uint64] ##\
     ## Validator balances in Gwei!
 
     validator_registry_update_epoch*: Epoch
@@ -410,7 +410,7 @@ type
 
     # Ethereum 1.0 chain data
     latest_eth1_data*: Eth1Data
-    eth1_data_votes*: seq[Eth1DataVote]
+    eth1_data_votes*: seq[Eth1Data]
     deposit_index*: uint64
 
   # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#validator
@@ -436,22 +436,25 @@ type
     slashed*: bool ##\
     ## Was the validator slashed
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#crosslink
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#crosslink
   Crosslink* = object
     epoch*: Epoch ##\
     ## Epoch number
 
+    previous_crosslink_root*: Eth2Digest ##\
+    ## Root of the previous crosslink
+
     crosslink_data_root*: Eth2Digest ##\
     ## Shard data since the previous crosslink
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#pendingattestation
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#pendingattestation
   PendingAttestation* = object
     aggregation_bitfield*: BitField           ## Attester participation bitfield
     data*: AttestationData                    ## Attestation data
-    custody_bitfield*: BitField               ## Custody bitfield
     inclusion_slot*: Slot                     ## Inclusion slot
+    proposer_index*: ValidatorIndex           ## Proposer index
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#historicalbatch
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#historicalbatch
   HistoricalBatch* = object
     block_roots* : array[SLOTS_PER_HISTORICAL_ROOT, Eth2Digest] ##\
     ## Block roots
@@ -459,7 +462,7 @@ type
     state_roots* : array[SLOTS_PER_HISTORICAL_ROOT, Eth2Digest] ##\
     ## State roots
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#fork
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#fork
   Fork* = object
     previous_version*: array[4, byte] ##\
     ## Previous fork version
@@ -470,31 +473,26 @@ type
     epoch*: Epoch ##\
     ## Fork epoch number
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#eth1data
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#eth1data
   Eth1Data* = object
     deposit_root*: Eth2Digest ##\
     ## Data being voted for
 
+    deposit_count*: uint64 ##\
+    ## Total number of deposits
+
     block_hash*: Eth2Digest ##\
     ## Block hash
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#eth1datavote
-  Eth1DataVote* = object
-    eth1_data*: Eth1Data ##\
-    ## Data being voted for
-
-    vote_count*: uint64 ##\
-    ## Vote count
-
   ## TODO remove or otherwise conditional-compile this, since it's for light
   ## client but not in spec
   ValidatorSetDeltaFlags* {.pure.} = enum
     Activation = 0
     Exit = 1
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#signature-domains
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#signature-domains
   SignatureDomain* {.pure.} = enum
-    DOMAIN_BEACON_BLOCK = 0
+    DOMAIN_BEACON_PROPOSER = 0
     DOMAIN_RANDAO = 1
     DOMAIN_ATTESTATION = 2
     DOMAIN_DEPOSIT = 3
diff --git a/beacon_chain/spec/digest.nim b/beacon_chain/spec/digest.nim
index c42eb0f19..15c46d2df 100644
--- a/beacon_chain/spec/digest.nim
+++ b/beacon_chain/spec/digest.nim
@@ -7,7 +7,7 @@
 
 # Serenity hash function / digest
 #
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#hash
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#hash
 #
 # In Phase 0 the beacon chain is deployed with the same hash function as
 # Ethereum 1.0, i.e. Keccak-256 (also incorrectly known as SHA3).
diff --git a/beacon_chain/spec/helpers.nim b/beacon_chain/spec/helpers.nim
index cb05bf36f..d1389f05c 100644
--- a/beacon_chain/spec/helpers.nim
+++ b/beacon_chain/spec/helpers.nim
@@ -18,7 +18,7 @@ func split*[T](lst: openArray[T], N: Positive): seq[seq[T]] =
   for i in 0 ..< N:
     result[i] = lst[lst.len * i div N ..< lst.len * (i+1) div N] # TODO: avoid alloc via toOpenArray
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#integer_squareroot
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#integer_squareroot
 func integer_squareroot*(n: SomeInteger): SomeInteger =
   ## The largest integer ``x`` such that ``x**2`` is less than ``n``.
   doAssert n >= 0'u64
@@ -31,14 +31,6 @@ func integer_squareroot*(n: SomeInteger): SomeInteger =
     y = (x + n div x) div 2
   x
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#get_fork_version
-func get_fork_version*(fork: Fork, epoch: Epoch): array[4, byte] =
-  ## Return the fork version of the given ``epoch``.
-  if epoch < fork.epoch:
-    fork.previous_version
-  else:
-    fork.current_version
-
 # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#is_power_of_two
 func is_power_of_2*(v: uint64): bool = (v > 0'u64) and (v and (v-1)) == 0
 
@@ -77,40 +69,38 @@ func merkle_root*(values: openArray[Eth2Digest]): Eth2Digest =
 
   o[1]
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#slot_to_epoch
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#slot_to_epoch
 func slot_to_epoch*(slot: Slot|uint64): Epoch =
   (slot div SLOTS_PER_EPOCH).Epoch
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#get_epoch_start_slot
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#get_epoch_start_slot
 func get_epoch_start_slot*(epoch: Epoch): Slot =
   # Return the starting slot of the given ``epoch``.
   (epoch * SLOTS_PER_EPOCH).Slot
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#is_double_vote
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#is_double_vote
 func is_double_vote*(attestation_data_1: AttestationData,
                      attestation_data_2: AttestationData): bool =
   ## Check if ``attestation_data_1`` and ``attestation_data_2`` have the same
   ## target.
   let
-    # RLP artifact
     target_epoch_1 = slot_to_epoch(attestation_data_1.slot)
     target_epoch_2 = slot_to_epoch(attestation_data_2.slot)
   target_epoch_1 == target_epoch_2
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#is_surround_vote
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#is_surround_vote
 func is_surround_vote*(attestation_data_1: AttestationData,
                        attestation_data_2: AttestationData): bool =
   ## Check if ``attestation_data_1`` surrounds ``attestation_data_2``.
   let
     source_epoch_1 = attestation_data_1.source_epoch
     source_epoch_2 = attestation_data_2.source_epoch
-    # RLP artifact
     target_epoch_1 = slot_to_epoch(attestation_data_1.slot)
     target_epoch_2 = slot_to_epoch(attestation_data_2.slot)
 
   source_epoch_1 < source_epoch_2 and target_epoch_2 < target_epoch_1
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#is_active_validator
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#state-list-lengths
 func is_active_validator*(validator: Validator, epoch: Epoch): bool =
   ### Check if ``validator`` is active
   validator.activation_epoch <= epoch and epoch < validator.exit_epoch
@@ -137,13 +127,13 @@ func get_current_epoch_committee_count*(state: BeaconState): uint64 =
   )
   get_epoch_committee_count(len(current_active_validators))
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#get_current_epoch
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#get_current_epoch
 func get_current_epoch*(state: BeaconState): Epoch =
   # Return the current epoch of the given ``state``.
   doAssert state.slot >= GENESIS_SLOT, $state.slot
   slot_to_epoch(state.slot)
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#get_randao_mix
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#get_randao_mix
 func get_randao_mix*(state: BeaconState,
                      epoch: Epoch): Eth2Digest =
     ## Returns the randao mix at a recent ``epoch``.
@@ -177,7 +167,7 @@ func bytes_to_int*(data: openarray[byte]): uint64 =
   for i in countdown(7, 0):
     result = result * 256 + data[i]
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#int_to_bytes1-int_to_bytes2-
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#int_to_bytes1-int_to_bytes2-
 # Have 1, 4, 8, and 32-byte versions. 1+ more and maybe worth metaprogramming.
 func int_to_bytes32*(x: uint64): array[32, byte] =
   ## Little-endian data representation
@@ -207,22 +197,31 @@ func int_to_bytes4*(x: uint64): array[4, byte] =
   result[2] = ((x shr 16) and 0xff).byte
   result[3] = ((x shr 24) and 0xff).byte
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#get_domain
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#get_domain
 func get_domain*(
-    fork: Fork, epoch: Epoch, domain_type: SignatureDomain): uint64 =
-  # Get the domain number that represents the fork meta and signature domain.
+    state: BeaconState, domain_type: SignatureDomain, message_epoch: Epoch): uint64 =
+  ## Return the signature domain (fork version concatenated with domain type)
+  ## of a message.
   var buf: array[8, byte]
-  buf[0..3] = get_fork_version(fork, epoch)
+  let
+    epoch = message_epoch
+    fork_version = if epoch < state.fork.epoch:
+        state.fork.previous_version
+      else:
+        state.fork.current_version
+  buf[0..3] = fork_version
   buf[4..7] = int_to_bytes4(domain_type.uint64)
   bytes_to_int(buf)
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#generate_seed
+func get_domain*(state: BeaconState, domain_type: SignatureDomain): uint64 =
+  get_domain(state, domain_type, get_current_epoch(state))
+
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#generate_seed
 func generate_seed*(state: BeaconState, epoch: Epoch): Eth2Digest =
   # Generate a seed for the given ``epoch``.
 
   var seed_input : array[32*3, byte]
 
-  # Cannot underflow, since GENESIS_EPOCH > MIN_SEED_LOOKAHEAD
   doAssert GENESIS_EPOCH > MIN_SEED_LOOKAHEAD
 
   seed_input[0..31] = get_randao_mix(state, epoch - MIN_SEED_LOOKAHEAD).data
diff --git a/beacon_chain/spec/validator.nim b/beacon_chain/spec/validator.nim
index 65e01686f..2f628c174 100644
--- a/beacon_chain/spec/validator.nim
+++ b/beacon_chain/spec/validator.nim
@@ -229,6 +229,7 @@ iterator get_crosslink_committees_at_slot_cached*(
   for v in result: yield v
 
 # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#get_beacon_proposer_index
+# TODO remove/merge these back together once 0.5.1 callers removed
 func get_beacon_proposer_index*(state: BeaconState, slot: Slot): ValidatorIndex =
   ## From Casper RPJ mini-spec:
   ## When slot i begins, validator Vidx is expected
@@ -255,3 +256,8 @@ func get_beacon_proposer_index*(state: BeaconState, slot: Slot): ValidatorIndex
   let (first_committee, _) = get_crosslink_committees_at_slot(state, slot)[0]
   let idx = int(slot mod uint64(first_committee.len))
   first_committee[idx]
+
+func get_beacon_proposer_index*(state: BeaconState): ValidatorIndex =
+  # Return the beacon proposer index at ``state.slot``.
+  # TODO there are some other changes here
+  get_beacon_proposer_index(state, state.slot)
diff --git a/beacon_chain/ssz.nim b/beacon_chain/ssz.nim
index 082674ade..6f4779a48 100644
--- a/beacon_chain/ssz.nim
+++ b/beacon_chain/ssz.nim
@@ -263,7 +263,7 @@ proc readValue*(r: var SszReader, result: var auto) =
 # ################### Hashing ###################################
 
 # Sample hash_tree_root implementation based on:
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.1/specs/simple-serialize.md
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/simple-serialize.md
 # https://github.com/ethereum/eth2.0-specs/blob/v0.5.1/utils/phase0/minimal_ssz.py
 # TODO Probably wrong - the spec is pretty bare-bones and no test vectors yet
 
diff --git a/beacon_chain/state_transition.nim b/beacon_chain/state_transition.nim
index c07aa6545..2cd5debf3 100644
--- a/beacon_chain/state_transition.nim
+++ b/beacon_chain/state_transition.nim
@@ -62,7 +62,7 @@ proc processBlockHeader(
       proposer.pubkey,
       signed_root(blck).data,
       blck.signature,
-      get_domain(state.fork, get_current_epoch(state), DOMAIN_BEACON_BLOCK)):
+      get_domain(state, DOMAIN_BEACON_PROPOSER, get_current_epoch(state))):
     notice "Block header: invalid block header",
       proposer_pubkey = proposer.pubkey,
       block_root = shortLog(signed_root(blck)),
@@ -83,7 +83,7 @@ proc processRandao(
       proposer.pubkey,
       hash_tree_root(get_current_epoch(state).uint64).data,
       blck.body.randao_reveal,
-      get_domain(state.fork, get_current_epoch(state), DOMAIN_RANDAO)):
+      get_domain(state, DOMAIN_RANDAO, get_current_epoch(state))):
 
       notice "Randao mismatch", proposer_pubkey = proposer.pubkey,
                                 message = get_current_epoch(state),
@@ -103,18 +103,12 @@ proc processRandao(
 
   true
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#eth1-data-1
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#eth1-data
 func processEth1Data(state: var BeaconState, blck: BeaconBlock) =
-  # TODO verify that there's at most one match
-  for x in state.eth1_data_votes.mitems():
-    if blck.body.eth1_data == x.eth1_data:
-      x.vote_count += 1
-      return
-
-  state.eth1_data_votes.add Eth1DataVote(
-    eth1_data: blck.body.eth1_data,
-    vote_count: 1
-  )
+  state.eth1_data_votes.add blck.body.eth1_data
+  if state.eth1_data_votes.count(blck.body.eth1_data) * 2 >
+      SLOTS_PER_ETH1_VOTING_PERIOD:
+    state.latest_eth1_data = blck.body.eth1_data
 
 # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#proposer-slashings
 proc processProposerSlashings(
@@ -147,7 +141,7 @@ proc processProposerSlashings(
             signed_root(header).data,
             header.signature,
             get_domain(
-              state.fork, slot_to_epoch(header.slot), DOMAIN_BEACON_BLOCK)):
+              state, DOMAIN_BEACON_PROPOSER, slot_to_epoch(header.slot))):
           notice "PropSlash: invalid signature",
             signature_index = i
           return false
@@ -157,7 +151,7 @@ proc processProposerSlashings(
   true
 
 # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#verify_slashable_attestation
-func verify_slashable_attestation(state: BeaconState, slashable_attestation: SlashableAttestation): bool =
+func verify_slashable_attestation(state: BeaconState, slashable_attestation: IndexedAttestation): bool =
   # Verify validity of ``slashable_attestation`` fields.
 
   if anyIt(slashable_attestation.custody_bitfield.bits, it != 0):   # [TO BE REMOVED IN PHASE 1]
@@ -174,7 +168,7 @@ func verify_slashable_attestation(state: BeaconState, slashable_attestation: Sla
       len(slashable_attestation.validator_indices)):
     return false
 
-  if len(slashable_attestation.validator_indices) > MAX_INDICES_PER_SLASHABLE_VOTE:
+  if len(slashable_attestation.validator_indices) > MAX_INDICES_PER_ATTESTATION:
     return false
 
   var
@@ -200,9 +194,9 @@ func verify_slashable_attestation(state: BeaconState, slashable_attestation: Sla
     ],
     slashable_attestation.aggregate_signature,
     get_domain(
-      state.fork,
-      slot_to_epoch(slashable_attestation.data.slot),
+      state,
       DOMAIN_ATTESTATION,
+      slot_to_epoch(slashable_attestation.data.slot),
     ),
   )
 
@@ -216,8 +210,8 @@ proc processAttesterSlashings(state: var BeaconState, blck: BeaconBlock): bool =
 
   for attester_slashing in blck.body.attester_slashings:
     let
-      slashable_attestation_1 = attester_slashing.slashable_attestation_1
-      slashable_attestation_2 = attester_slashing.slashable_attestation_2
+      slashable_attestation_1 = attester_slashing.attestation_1
+      slashable_attestation_2 = attester_slashing.attestation_2
 
     # Check that the attestations are conflicting
     if not (slashable_attestation_1.data != slashable_attestation_2.data):
@@ -253,7 +247,7 @@ proc processAttesterSlashings(state: var BeaconState, blck: BeaconBlock): bool =
 
   true
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.1/specs/core/0_beacon-chain.md#attestations
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#attestations
 proc processAttestations(
     state: var BeaconState, blck: BeaconBlock, flags: UpdateFlags): bool =
   ## Each block includes a number of attestations that the proposer chose. Each
@@ -275,8 +269,8 @@ proc processAttestations(
     let pending_attestation = PendingAttestation(
       data: attestation.data,
       aggregation_bitfield: attestation.aggregation_bitfield,
-      custody_bitfield: attestation.custody_bitfield,
-      inclusion_slot: state.slot
+      inclusion_slot: state.slot,
+      proposer_index: get_beacon_proposer_index(state),
     )
 
     if slot_to_epoch(attestation.data.slot) == get_current_epoch(state):
@@ -337,7 +331,7 @@ proc processExits(
     if skipValidation notin flags:
       if not bls_verify(
           validator.pubkey, signed_root(exit).data, exit.signature,
-          get_domain(state.fork, exit.epoch, DOMAIN_VOLUNTARY_EXIT)):
+          get_domain(state, DOMAIN_VOLUNTARY_EXIT, exit.epoch)):
         notice "Exit: invalid signature"
         return false
 
@@ -379,44 +373,38 @@ func update_registry_and_shuffling_data(state: var BeaconState) =
       state.current_shuffling_seed =
         generate_seed(state, state.current_shuffling_epoch)
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#transfers
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#transfers
 proc processTransfers(state: var BeaconState, blck: BeaconBlock,
                       flags: UpdateFlags): bool =
-  ## Note: Transfers are a temporary functionality for phases 0 and 1, to be
-  ## removed in phase 2.
   if not (len(blck.body.transfers) <= MAX_TRANSFERS):
     notice "Transfer: too many transfers"
     return false
 
   for transfer in blck.body.transfers:
-    let sender_balance = state.validator_balances[transfer.sender.int]
+    let sender_balance = state.balances[transfer.sender.int]
 
-    ## Verify the amount and fee aren't individually too big (for anti-overflow
+    ## Verify the amount and fee are not individually too big (for anti-overflow
     ## purposes)
     if not (sender_balance >= max(transfer.amount, transfer.fee)):
       notice "Transfer: sender balance too low for transfer amount or fee"
       return false
 
-    ## Verify that we have enough ETH to send, and that after the transfer the
-    ## balance will be either exactly zero or at least MIN_DEPOSIT_AMOUNT
-    if not (
-        sender_balance == transfer.amount + transfer.fee or
-        sender_balance >= transfer.amount + transfer.fee + MIN_DEPOSIT_AMOUNT):
-      notice "Transfer: sender balance too low for amount + fee"
-      return false
-
     # A transfer is valid in only one slot
     if not (state.slot == transfer.slot):
       notice "Transfer: slot mismatch"
       return false
 
-    # Only withdrawn or not-yet-deposited accounts can transfer
-    if not (get_current_epoch(state) >=
+    ## Sender must be not yet eligible for activation, withdrawn, or transfer
+    ## balance over MAX_EFFECTIVE_BALANCE
+    if not (
+      state.validator_registry[transfer.sender.int].activation_epoch ==
+        FAR_FUTURE_EPOCH or
+      get_current_epoch(state) >=
         state.validator_registry[
           transfer.sender.int].withdrawable_epoch or
-        state.validator_registry[transfer.sender.int].activation_epoch ==
-          FAR_FUTURE_EPOCH):
-      notice "Transfer: only withdrawn or not-deposited accounts can transfer"
+      transfer.amount + transfer.fee + MAX_EFFECTIVE_BALANCE <=
+        state.balances[transfer.sender.int]):
+      notice "Transfer: only withdrawn or not-activated accounts with sufficient balance can transfer"
       return false
 
     # Verify that the pubkey is valid
@@ -431,18 +419,29 @@ proc processTransfers(state: var BeaconState, blck: BeaconBlock,
     if skipValidation notin flags:
       if not bls_verify(
           transfer.pubkey, signed_root(transfer).data, transfer.signature,
-          get_domain(
-            state.fork, slot_to_epoch(transfer.slot), DOMAIN_TRANSFER)):
+          get_domain(state, DOMAIN_TRANSFER)):
         notice "Transfer: incorrect signature"
         return false
 
-    # TODO https://github.com/ethereum/eth2.0-specs/issues/727
-    reduce_balance(
-      state.validator_balances[transfer.sender.int],
-      transfer.amount + transfer.fee)
-    state.validator_balances[transfer.recipient.int] += transfer.amount
-    state.validator_balances[
-      get_beacon_proposer_index(state, state.slot)] += transfer.fee
+    # Process the transfer
+    decrease_balance(
+      state, transfer.sender.ValidatorIndex, transfer.amount + transfer.fee)
+    increase_balance(
+      state, transfer.recipient.ValidatorIndex, transfer.amount)
+    increase_balance(state, get_beacon_proposer_index(state), transfer.fee)
+
+    # Verify balances are not dust
+    if not (
+        0'u64 < state.balances[transfer.sender.int] and
+        state.balances[transfer.sender.int] < MIN_DEPOSIT_AMOUNT):
+      notice "Transfer: sender balance too low for transfer amount or fee"
+      return false
+
+    if not (
+        0'u64 < state.balances[transfer.recipient.int] and
+        state.balances[transfer.recipient.int] < MIN_DEPOSIT_AMOUNT):
+      notice "Transfer: sender balance too low for transfer amount or fee"
+      return false
 
   true
 
@@ -772,17 +771,6 @@ func process_crosslinks(
           crosslink_data_root: winning_root
         )
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#eth1-data
-func maybe_reset_eth1_period(state: var BeaconState) =
-  if (get_current_epoch(state) + 1) mod EPOCHS_PER_ETH1_VOTING_PERIOD == 0:
-    for eth1_data_vote in state.eth1_data_votes:
-      ## If a majority of all votes were for a particular eth1_data value,
-      ## then set that as the new canonical value
-      if eth1_data_vote.vote_count * 2 >
-          EPOCHS_PER_ETH1_VOTING_PERIOD * SLOTS_PER_EPOCH:
-        state.latest_eth1_data = eth1_data_vote.eth1_data
-    state.eth1_data_votes = @[]
-
 # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#rewards-and-penalties
 func get_base_reward(state: BeaconState, index: ValidatorIndex): uint64 =
   if get_previous_total_balance(state) == 0:
@@ -866,7 +854,7 @@ func compute_normal_justification_and_finalization_deltas(state: BeaconState):
       let proposer_index =
         get_beacon_proposer_index(state, inclusion_slot[index])
       deltas[0][proposer_index] +=
-        get_base_reward(state, index) div ATTESTATION_INCLUSION_REWARD_QUOTIENT
+        get_base_reward(state, index) div PROPOSER_REWARD_QUOTIENT
   deltas
 
 func compute_inactivity_leak_deltas(state: BeaconState):
@@ -981,10 +969,10 @@ func apply_rewards(state: var BeaconState, cache: var StateCache) =
     deltas1 = get_justification_and_finalization_deltas(state)
     deltas2 = get_crosslink_deltas(state, cache)
   for i in 0 ..< len(state.validator_registry):
-    state.validator_balances[i] =
+    state.balances[i] =
       max(
         0'u64,
-        state.validator_balances[i] + deltas1[0][i] + deltas2[0][i] -
+        state.balances[i] + deltas1[0][i] + deltas2[0][i] -
                                       deltas1[1][i] - deltas2[1][i])
 
 # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#slashings-and-exit-queue
@@ -1014,7 +1002,7 @@ func process_slashings(state: var BeaconState) =
             min(total_penalties * 3, total_balance) div total_balance,
           get_effective_balance(state, index.ValidatorIndex) div
             MIN_PENALTY_QUOTIENT)
-      reduce_balance(state.validator_balances[index], penalty)
+      reduce_balance(state.balances[index], penalty)
 
 func process_exit_queue(state: var BeaconState) =
   ## Process the exit queue.
@@ -1045,7 +1033,7 @@ func process_exit_queue(state: var BeaconState) =
             state.validator_registry[y].exit_epoch))
 
     for dequeues, index in sorted_indices:
-      if dequeues >= MAX_EXIT_DEQUEUES_PER_EPOCH:
+      if dequeues >= MIN_PER_EPOCH_CHURN_LIMIT:
         break
       prepare_validator_for_withdrawal(state, index)
 
@@ -1104,9 +1092,6 @@ func processEpoch(state: var BeaconState) =
   # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#crosslinks
   process_crosslinks(state, per_epoch_cache)
 
-  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#eth1-data
-  maybe_reset_eth1_period(state)
-
   # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#apply-rewards
   apply_rewards(state, per_epoch_cache)
 
@@ -1124,7 +1109,7 @@ func processEpoch(state: var BeaconState) =
   # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#final-updates
   finish_epoch_update(state)
 
-# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#state-root-verification
+# https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_beacon-chain.md#state-root-verification
 proc verifyStateRoot(state: BeaconState, blck: BeaconBlock): bool =
   let state_root = hash_tree_root(state)
   if state_root != blck.state_root:
diff --git a/beacon_chain/time.nim b/beacon_chain/time.nim
index 84062e64b..f7e4867af 100644
--- a/beacon_chain/time.nim
+++ b/beacon_chain/time.nim
@@ -14,7 +14,7 @@ type
     ## which blocks are valid - in particular, blocks are not valid if they
     ## come from the future as seen from the local clock.
     ##
-    ## https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#beacon-chain-processing
+    ## https://github.com/ethereum/eth2.0-specs/blob/v0.6.0/specs/core/0_fork-choice.md#beacon-chain-processing
     ##
     # TODO replace time in chronos with a proper unit type, then this code can
     #      follow:
diff --git a/beacon_chain/validator_keygen.nim b/beacon_chain/validator_keygen.nim
index 0245b59fa..0a425d0cc 100644
--- a/beacon_chain/validator_keygen.nim
+++ b/beacon_chain/validator_keygen.nim
@@ -45,7 +45,7 @@ cli do (totalValidators: int = 125000,
     let
       deposit = Deposit(
         deposit_data: DepositData(
-          amount: MAX_DEPOSIT_AMOUNT,
+          amount: MAX_EFFECTIVE_BALANCE,
           timestamp: 0, # TODO https://github.com/ethereum/eth2.0-specs/pull/834
           deposit_input: DepositInput(
             pubkey: pubKey,
diff --git a/beacon_chain/validator_pool.nim b/beacon_chain/validator_pool.nim
index 057858820..1c0fb489e 100644
--- a/beacon_chain/validator_pool.nim
+++ b/beacon_chain/validator_pool.nim
@@ -25,12 +25,12 @@ proc getValidator*(pool: ValidatorPool,
                    validatorKey: ValidatorPubKey): AttachedValidator =
   pool.validators.getOrDefault(validatorKey)
 
-proc signBlockProposal*(v: AttachedValidator, fork: Fork, slot: Slot,
+proc signBlockProposal*(v: AttachedValidator, state: BeaconState, slot: Slot,
                         blockRoot: Eth2Digest): Future[ValidatorSig] {.async.} =
   if v.kind == inProcess:
     await sleepAsync(chronos.milliseconds(1))
     result = bls_sign(v.privKey, blockRoot.data,
-      get_domain(fork, slot_to_epoch(slot), DOMAIN_BEACON_BLOCK))
+      get_domain(state, DOMAIN_BEACON_PROPOSER, slot_to_epoch(slot)))
   else:
     # TODO:
     # send RPC
@@ -60,7 +60,7 @@ func genRandaoReveal*(k: ValidatorPrivKey, state: BeaconState, slot: Slot):
   # Off-by-one? I often get slot == state.slot but the check was "doAssert slot > state.slot" (Mamy)
   doAssert slot >= state.slot, "input slot: " & $humaneSlotNum(slot) & " - beacon state slot: " & $humaneSlotNum(state.slot)
   bls_sign(k, hash_tree_root(slot_to_epoch(slot).uint64).data,
-    get_domain(state.fork, slot_to_epoch(slot), DOMAIN_RANDAO))
+    get_domain(state, DOMAIN_RANDAO, slot_to_epoch(slot)))
 
 func genRandaoReveal*(v: AttachedValidator, state: BeaconState, slot: Slot):
     ValidatorSig =
diff --git a/tests/all_tests.nim b/tests/all_tests.nim
index c81415b1c..6b7ad24e0 100644
--- a/tests/all_tests.nim
+++ b/tests/all_tests.nim
@@ -16,5 +16,7 @@ import
   ./test_ssz,
   ./test_state_transition,
   ./test_sync_protocol,
-  ./test_validator,
-  ./official/test_fixture_state
+  ./test_validator
+
+  # TODO - re-enable once official test fixtures arrive
+  #./official/test_fixture_state
diff --git a/tests/official/state_test_utils.nim b/tests/official/state_test_utils.nim
index ff8683611..bac339e81 100644
--- a/tests/official/state_test_utils.nim
+++ b/tests/official/state_test_utils.nim
@@ -23,12 +23,12 @@ type
     SHARD_COUNT*: int
     TARGET_COMMITTEE_SIZE*: int
     MAX_BALANCE_CHURN_QUOTIENT*: int
-    MAX_INDICES_PER_SLASHABLE_VOTE*: int
-    MAX_EXIT_DEQUEUES_PER_EPOCH*: int
+    MAX_INDICES_PER_ATTESTATION*: int
+    MIN_PER_EPOCH_CHURN_LIMIT*: int
     SHUFFLE_ROUND_COUNT*: int
     DEPOSIT_CONTRACT_TREE_DEPTH*: int
     MIN_DEPOSIT_AMOUNT*: uint64
-    MAX_DEPOSIT_AMOUNT*: uint64
+    MAX_EFFECTIVE_BALANCE*: uint64
     FORK_CHOICE_BALANCE_INCREMENT*: uint64
     EJECTION_BALANCE*: uint64
     GENESIS_FORK_VERSION*: uint32
@@ -50,7 +50,7 @@ type
     LATEST_SLASHED_EXIT_LENGTH*: int
     BASE_REWARD_QUOTIENT*: uint64
     WHISTLEBLOWER_REWARD_QUOTIENT*: uint64
-    ATTESTATION_INCLUSION_REWARD_QUOTIENT*: uint64
+    PROPOSER_REWARD_QUOTIENT*: uint64
     INACTIVITY_PENALTY_QUOTIENT*: uint64
     MIN_PENALTY_QUOTIENT*: int
     MAX_PROPOSER_SLASHINGS*: int
@@ -59,7 +59,7 @@ type
     MAX_DEPOSITS*: int
     MAX_VOLUNTARY_EXITS*: int
     MAX_TRANSFERS*: int
-    DOMAIN_BEACON_BLOCK*: SignatureDomain
+    DOMAIN_BEACON_PROPOSER*: SignatureDomain
     DOMAIN_RANDAO*: SignatureDomain
     DOMAIN_ATTESTATION*: SignatureDomain
     DOMAIN_DEPOSIT*: SignatureDomain
diff --git a/tests/test_ssz.nim b/tests/test_ssz.nim
index b591c1a10..958c5cd63 100644
--- a/tests/test_ssz.nim
+++ b/tests/test_ssz.nim
@@ -86,10 +86,10 @@ suite "Tree hashing":
     let vr = BeaconBlock()
     check:
       $hash_tree_root(vr) ==
-        "1BD5D8577A7806CC524C367808C53AE2480F35A3C4BB11A90D6E1AC304E27201"
+        "8951C9C64ABA469EBA78F5D9F9A0666FB697B8C4D86901445777E4445D0B1543"
 
   test "Hash BeaconState":
     let vr = BeaconState()
     check:
       $hash_tree_root(vr) ==
-        "17E30FC7BC442CEF2045C4FB3CC6B1D975F041C4629DA7395B607281FD1521A6"
+        "66F9BF92A690F1FBD36488D98BE70DA6C84100EDF935BC6D0B30FF14A2976455"
diff --git a/tests/testutil.nim b/tests/testutil.nim
index d17d50949..867912b55 100644
--- a/tests/testutil.nim
+++ b/tests/testutil.nim
@@ -56,7 +56,7 @@ func makeDeposit(i: int, flags: UpdateFlags): Deposit =
         proof_of_possession: pop,
         withdrawal_credentials: withdrawal_credentials,
       ),
-      amount: MAX_DEPOSIT_AMOUNT,
+      amount: MAX_EFFECTIVE_BALANCE,
     )
   )
 
@@ -128,12 +128,12 @@ proc addBlock*(
     # We have a signature - put it in the block and we should be done!
     new_block.signature =
       bls_sign(proposerPrivkey, block_root.data,
-               get_domain(state.fork, slot_to_epoch(new_block.slot), DOMAIN_BEACON_BLOCK))
+               get_domain(state, DOMAIN_BEACON_PROPOSER, slot_to_epoch(new_block.slot)))
 
     doAssert bls_verify(
       proposer.pubkey,
       block_root.data, new_block.signature,
-      get_domain(state.fork, slot_to_epoch(new_block.slot), DOMAIN_BEACON_BLOCK)),
+      get_domain(state, DOMAIN_BEACON_PROPOSER, slot_to_epoch(new_block.slot))),
       "we just signed this message - it should pass verification!"
 
   new_block
@@ -178,9 +178,9 @@ proc makeAttestation*(
         bls_sign(
           hackPrivKey(validator), @(msg.data),
           get_domain(
-            state.fork,
-            slot_to_epoch(state.slot),
-            DOMAIN_ATTESTATION))
+            state,
+            DOMAIN_ATTESTATION,
+            slot_to_epoch(state.slot)))
       else:
         ValidatorSig()