diff --git a/app/lib/simulator/Simulator.coffee b/app/lib/simulator/Simulator.coffee
index 9805f38bc..2ec95bfef 100644
--- a/app/lib/simulator/Simulator.coffee
+++ b/app/lib/simulator/Simulator.coffee
@@ -5,9 +5,23 @@ GoalManager = require 'lib/world/GoalManager'
 God = require 'lib/God'
 {createAetherOptions} = require 'lib/aether_utils'
 
+SIMULATOR_VERSION = 1
+
+simulatorInfo = {}
+if $.browser
+  simulatorInfo['desktop'] = $.browser.desktop if $.browser.desktop
+  simulatorInfo['name'] = $.browser.name if $.browser.name
+  simulatorInfo['platform'] = $.browser.platform if $.browser.platform
+  simulatorInfo['version'] = $.browser.versionNumber if $.browser.versionNumber
+
 module.exports = class Simulator extends CocoClass
   constructor: (@options) ->
     @options ?= {}
+    simulatorType = if @options.headlessClient then 'headless' else 'browser'
+    @simulator =
+      type: simulatorType
+      version: SIMULATOR_VERSION
+      info: simulatorInfo
     _.extend @, Backbone.Events
     @trigger 'statusUpdate', 'Starting simulation!'
     @retryDelayInSeconds = 2
@@ -28,10 +42,17 @@ module.exports = class Simulator extends CocoClass
       type: 'POST'
       parse: true
       data:
-        'humansGameID': humanGameID
-        'ogresGameID': ogresGameID
+        humansGameID: humanGameID
+        ogresGameID: ogresGameID
+        simulator: @simulator
       error: (errorData) ->
         console.warn "There was an error fetching two games! #{JSON.stringify errorData}"
+        if errorData?.responseText?.indexOf("Old simulator") isnt -1
+          noty {
+            text: errorData.responseText
+            layout: 'center'
+            type: 'error'
+          }
       success: (taskData) =>
         return if @destroyed
         unless taskData
@@ -278,7 +299,6 @@ module.exports = class Simulator extends CocoClass
     return if @destroyed
     console.log "Task registration result: #{JSON.stringify result}"
     @trigger 'statusUpdate', 'Results were successfully sent back to server!'
-    console.log 'Simulated by you:', @simulatedByYou
     @simulatedByYou++
     unless @options.headlessClient
       simulatedBy = parseInt($('#simulated-by-you').text(), 10) + 1
@@ -307,6 +327,7 @@ module.exports = class Simulator extends CocoClass
       originalSessionRank: -1
       calculationTime: 500
       sessions: []
+      simulator: @simulator
 
     for session in @task.getSessions()
       sessionResult =
diff --git a/app/schemas/models/level_session.coffee b/app/schemas/models/level_session.coffee
index 6942b8f6b..41f585f43 100644
--- a/app/schemas/models/level_session.coffee
+++ b/app/schemas/models/level_session.coffee
@@ -285,6 +285,7 @@ _.extend LevelSessionSchema.properties,
               codeLanguage:
                 type: ['string', 'null']  # 'null' in case an opponent session got corrupted, don't care much here
                 description: 'What submittedCodeLanguage the opponent used during the match'
+        simulator: {type: 'object', description: 'Holds info on who simulated the match, and with what tools.'}
 
 c.extendBasicProperties LevelSessionSchema, 'level.session'
 c.extendPermissionsProperties LevelSessionSchema, 'level.session'
diff --git a/app/templates/play/ladder/my_matches_tab.jade b/app/templates/play/ladder/my_matches_tab.jade
index bf4d9e856..5c1a12543 100644
--- a/app/templates/play/ladder/my_matches_tab.jade
+++ b/app/templates/play/ladder/my_matches_tab.jade
@@ -31,7 +31,7 @@ div#columns.row
           th(data-i18n="general.when") When
           th
         for match in team.matches
-          tr(class=(match.stale ? "stale " : "") + (match.fresh ? "fresh " : "") + match.state)
+          tr(class=(match.stale ? "stale " : "") + (match.fresh ? "fresh " : "") + match.state, title=match.simulator)
             td.state-cell
               if match.state === 'win'
                 span(data-i18n="general.win").win Win
diff --git a/app/views/ladder/MyMatchesTabView.coffee b/app/views/ladder/MyMatchesTabView.coffee
index eebc92ab8..ecc2370e0 100644
--- a/app/views/ladder/MyMatchesTabView.coffee
+++ b/app/views/ladder/MyMatchesTabView.coffee
@@ -72,6 +72,7 @@ module.exports = class MyMatchesTabView extends CocoView
         stale: match.date < submitDate
         fresh: fresh
         codeLanguage: match.codeLanguage
+        simulator: JSON.stringify(match.simulator)
       }
 
     for team in @teams
diff --git a/server/queues/scoring.coffee b/server/queues/scoring.coffee
index f97403e1d..74f822243 100644
--- a/server/queues/scoring.coffee
+++ b/server/queues/scoring.coffee
@@ -15,6 +15,8 @@ bayes = new (require 'bayesian-battle')()
 scoringTaskQueue = undefined
 scoringTaskTimeoutInSeconds = 600
 
+SIMULATOR_VERSION = 1
+
 module.exports.setup = (app) -> connectToScoringQueue()
 
 connectToScoringQueue = ->
@@ -124,6 +126,7 @@ module.exports.getTwoGames = (req, res) ->
   #if userIsAnonymous req then return errors.unauthorized(res, 'You need to be logged in to get games.')
   humansGameID = req.body.humansGameID
   ogresGameID = req.body.ogresGameID
+  return if simulatorIsTooOld req, res
   #ladderGameIDs = ['greed', 'criss-cross', 'brawlwood', 'dungeon-arena', 'gold-rush', 'sky-span']  # Let's not give any extra simulations to old ladders.
   ladderGameIDs = ['dueling-grounds', 'cavern-survival', 'multiplayer-treasure-grove']
   levelID = _.sample ladderGameIDs
@@ -224,6 +227,8 @@ module.exports.getTwoGames = (req, res) ->
 module.exports.recordTwoGames = (req, res) ->
   sessions = req.body.sessions
   #console.log 'Recording non-chained result of', sessions?[0]?.name, sessions[0]?.metrics?.rank, 'and', sessions?[1]?.name, sessions?[1]?.metrics?.rank
+  return if simulatorIsTooOld req, res
+  req.body?.simulator?.user = '' + req.user?._id
 
   yetiGuru = clientResponseObject: req.body, isRandomMatch: true
   async.waterfall [
@@ -442,7 +447,9 @@ getSessionInformation = (sessionIDString, callback) ->
     callback null, session
 
 module.exports.processTaskResult = (req, res) ->
+  return if simulatorIsTooOld req, res
   originalSessionID = req.body?.originalSessionID
+  req.body?.simulator?.user = '' + req.user?._id
   yetiGuru = {}
   try
     async.waterfall [
@@ -578,14 +585,14 @@ addMatchToSessions = (newScoreObject, callback) ->
   matchObject.opponents = {}
   for session in @clientResponseObject.sessions
     sessionID = session.sessionID
-    matchObject.opponents[sessionID] = {}
-    matchObject.opponents[sessionID].sessionID = sessionID
-    matchObject.opponents[sessionID].userID = session.creator
-    matchObject.opponents[sessionID].name = session.name
-    matchObject.opponents[sessionID].totalScore = session.totalScore
-    matchObject.opponents[sessionID].metrics = {}
-    matchObject.opponents[sessionID].metrics.rank = Number(newScoreObject[sessionID]?.gameRanking ? 0)
-    matchObject.opponents[sessionID].codeLanguage = newScoreObject[sessionID].submittedCodeLanguage
+    matchObject.opponents[sessionID] = match = {}
+    match.sessionID = sessionID
+    match.userID = session.creator
+    match.name = session.name
+    match.totalScore = session.totalScore
+    match.metrics = {}
+    match.metrics.rank = Number(newScoreObject[sessionID]?.gameRanking ? 0)
+    match.codeLanguage = newScoreObject[sessionID].submittedCodeLanguage
 
   #log.info "Match object computed, result: #{matchObject}"
   #log.info 'Writing match object to database...'
@@ -603,6 +610,7 @@ updateMatchesInSession = (matchObject, sessionID, callback) ->
   opponentsArray = _.toArray opponentsClone
   currentMatchObject.opponents = opponentsArray
   currentMatchObject.codeLanguage = matchObject.opponents[opponentsArray[0].sessionID].codeLanguage
+  currentMatchObject.simulator = @clientResponseObject.simulator
   LevelSession.findOne {'_id': sessionID}, (err, session) ->
     session = session.toObject()
     currentMatchObject.playtime = session.playtime ? 0
@@ -785,3 +793,12 @@ retrieveOldSessionData = (sessionID, callback) ->
 markSessionAsDoneRanking = (sessionID, cb) ->
   #console.log 'Marking session as done ranking...'
   LevelSession.update {'_id': sessionID}, {'isRanking': false}, cb
+
+simulatorIsTooOld = (req, res) ->
+  clientSimulator = req.body.simulator
+  return false if clientSimulator?.version >= SIMULATOR_VERSION
+  message = "Old simulator version #{clientSimulator?.version}, need to clear cache and get version #{SIMULATOR_VERSION}."
+  log.debug "400: #{message}"
+  res.send 400, message
+  res.end()
+  true
diff --git a/server_setup.coffee b/server_setup.coffee
index df81d50a0..ab99f4a04 100644
--- a/server_setup.coffee
+++ b/server_setup.coffee
@@ -50,7 +50,7 @@ setupErrorMiddleware = (app) ->
       res.status(err.status ? 500).send(error: "Something went wrong!")
       message = "Express error: #{req.method} #{req.path}: #{err.message}"
       log.error "#{message}, stack: #{err.stack}"
-      hipchat.sendTowerHipChatMessage(message)
+      hipchat.sendHipChatMessage(message, ['tower'], {papertrail: true})
     else
       next(err)
 setupExpressMiddleware = (app) ->