diff --git a/beacon_chain/fork_choice_rule/fork_choice_rule.nim b/beacon_chain/fork_choice_rule/fork_choice_rule.nim
index a9a0c284f..eaac7043f 100644
--- a/beacon_chain/fork_choice_rule/fork_choice_rule.nim
+++ b/beacon_chain/fork_choice_rule/fork_choice_rule.nim
@@ -17,15 +17,7 @@ import
   # Nimble packages
   nimcrypto,
   # Local imports
-  ./fork_choice_types, ./networksim
-
-###########################################################
-# Forward declarations
-
-method on_receive(self: Node, obj: BlockOrSig, reprocess = false) {.base.} =
-  raise newException(ValueError, "Not implemented error. Please implement in child types")
-
-###########################################################
+  ./fork_choice_types
 
 proc broadcast(self: Node, x: BlockOrSig) =
   if self.sleepy and self.timestamp != DurationZero:
@@ -48,8 +40,8 @@ func add_to_multiset[K, V](
     multiset: TableRef[K, seq[V]],
     k: K,
     v: V or seq[V]) =
-  if k notin multiset:
-    multiset[k] = @[]
+  # if k notin multiset: # Unneeded with seq "not nil" changes
+  #   multiset[k] = @[]
   multiset[k].add v
 
 func change_head(self: Node, chain: var seq[MDigest[256]], new_head: Block) =
@@ -241,7 +233,7 @@ func get_sig_targets(self: Node, start_slot: int32): seq[MDigest[256]] =
     doAssert self.blocks[x].slot <= start_slot - 1 - i
   doAssert result.len == min(EPOCH_LENGTH, start_slot)
 
-proc tick(self: Node) =
+proc tick*(self: Node) =
   self.timestamp += initDuration(milliseconds = 100)
   self.log &"Tick: {self.timestamp}", lvl=1
   # Make a block?
diff --git a/beacon_chain/fork_choice_rule/fork_choice_types.nim b/beacon_chain/fork_choice_rule/fork_choice_types.nim
index 19def8a37..1b1a4c987 100644
--- a/beacon_chain/fork_choice_rule/fork_choice_types.nim
+++ b/beacon_chain/fork_choice_rule/fork_choice_types.nim
@@ -107,7 +107,7 @@ type
     agents*: seq[Node]
     latency_distribution_sample*: proc (): Duration
     time*: Duration
-    objqueue*: TableRef[Duration, seq[(Node, BlockOrSig)]]
+    objqueue*: TableRef[Duration, seq[tuple[recipient: Node, obj: BlockOrSig]]]
     peers*: TableRef[int, seq[Node]]
     reliability*: float
 
@@ -153,3 +153,23 @@ proc initSig*(
   result.timestamp = ts
   for val in result.hash.data.mitems:
     val = rand(0.byte .. 7.byte)
+
+###########################################################
+# Forward declarations
+
+method on_receive*(self: Node, obj: BlockOrSig, reprocess = false) {.base.} =
+  raise newException(ValueError, "Not implemented error. Please implement in child types")
+
+###########################################################
+
+###########################################################
+# Common
+
+func broadcast*(self: NetworkSimulator, sender: Node, obj: BlockOrSig) =
+  for p in self.peers[sender.id]:
+    let recv_time = self.time + self.latency_distribution_sample()
+    if recv_time notin self.objqueue:
+      self.objqueue[recv_time] = @[]
+    self.objqueue[recv_time].add (p, obj)
+
+###########################################################
diff --git a/beacon_chain/fork_choice_rule/networksim.nim b/beacon_chain/fork_choice_rule/networksim.nim
index 3db580cd4..0bac77a6a 100644
--- a/beacon_chain/fork_choice_rule/networksim.nim
+++ b/beacon_chain/fork_choice_rule/networksim.nim
@@ -11,7 +11,7 @@
 
 import
   tables, times, sugar, random,
-  ./fork_choice_types, ./distributions
+  ./fork_choice_types, ./fork_choice_rule, ./distributions
 
 proc initNetworkSimulator*(latency: int): NetworkSimulator =
   result.latency_distribution_sample = () => initDuration(
@@ -37,9 +37,50 @@ proc generate_peers*(self: NetworkSimulator, num_peers = 5) =
     for peer in p:
       self.peers[peer.id].add a
 
-func broadcast*(self: NetworkSimulator, sender: Node, obj: BlockOrSig) =
-  for p in self.peers[sender.id]:
-    let recv_time = self.time + self.latency_distribution_sample()
-    if recv_time notin self.objqueue:
-      self.objqueue[recv_time] = @[]
-    self.objqueue[recv_time].add (p, obj)
+proc tick(self: NetworkSimulator) =
+  if self.time in self.objqueue:
+    for ro in self.objqueue[self.time]:
+      let (recipient, obj) = ro
+      if rand(1.0) < self.reliability:
+        recipient.on_receive(obj)
+    self.objqueue.del self.time
+  for a in self.agents:
+    a.tick()
+  self.time += initDuration(seconds = 1)
+
+proc run(self: NetworkSimulator, steps: int) =
+  for i in 0 ..< steps:
+    self.tick()
+
+# func broadcast*(self: NetworkSimulator, sender: Node, obj: BlockOrSig)
+#   ## defined in fork_choice_types.nim
+
+proc direct_send(self: NetworkSimulator, to_id: int32, obj: BlockOrSig) =
+  for a in self.agents:
+    if a.id == to_id:
+      let recv_time = self.time + self.latency_distribution_sample()
+      # if recv_time notin self.objqueue: # Unneeded with seq "not nil" changes
+      #   self.objqueue[recv_time] = @[]
+      self.objqueue[recv_time].add (a, obj)
+
+proc knock_offline_random(self: NetworkSimulator, n: int) =
+  var ko = initTable[int32, Node]()
+  while ko.len < n:
+    let c = rand(self.agents)
+    ko[c.id] = c
+  # for c in ko.values: # Unneeded with seq "not nil" changes
+  #   self.peers[c.id] = @[]
+  for a in self.agents:
+    self.peers[a.id] = lc[x | (x <- self.peers[a.id], x.id notin ko), Node] # List comprehension
+
+proc partition(self: NetworkSimulator) =
+  var a = initTable[int32, Node]()
+  while a.len < self.agents.len div 2:
+    let c = rand(self.agents)
+    a[c.id] = c
+  for c in self.agents:
+    if c.id in a:
+      self.peers[c.id] = lc[x | (x <- self.peers[c.id], x.id in a), Node]
+    else:
+      self.peers[c.id] = lc[x | (x <- self.peers[c.id], x.id notin a), Node]
+