diff --git a/app.js b/app.js
index 4d9134ce70..6781d8b6e4 100644
--- a/app.js
+++ b/app.js
@@ -226,7 +226,7 @@ global.ResourceMonitor = {
 			else if (typeof value === 'number') bytes += 8;
 			else if (typeof value === 'object' && objectList.indexOf( value ) === -1) {
 				objectList.push( value );
-				for (i in value) stack.push( value[ i ] );
+				for (var i in value) stack.push( value[ i ] );
 			}
 		}
 
diff --git a/battle-engine.js b/battle-engine.js
index 47631ec633..09fe0b157e 100644
--- a/battle-engine.js
+++ b/battle-engine.js
@@ -1046,6 +1046,7 @@ var BattlePokemon = (function() {
 		return this.battle.getNature(this.set.nature);
 	};
 	BattlePokemon.prototype.addVolatile = function(status, source, sourceEffect) {
+		var result;
 		if (!this.hp) return false;
 		status = this.battle.getEffect(status);
 		if (this.battle.event) {
@@ -1058,7 +1059,7 @@ var BattlePokemon = (function() {
 			return this.battle.singleEvent('Restart', status, this.volatiles[status.id], this, source, sourceEffect);
 		}
 		if (!this.runImmunity(status.id)) return false;
-		var result = this.battle.runEvent('TryAddVolatile', this, source, sourceEffect, status);
+		result = this.battle.runEvent('TryAddVolatile', this, source, sourceEffect, status);
 		if (!result) {
 			this.battle.debug('add volatile ['+status.id+'] interrupted');
 			return result;
@@ -1078,7 +1079,7 @@ var BattlePokemon = (function() {
 		if (status.durationCallback) {
 			this.volatiles[status.id].duration = status.durationCallback.call(this.battle, this, source, sourceEffect);
 		}
-		var result = this.battle.singleEvent('Start', status, this.volatiles[status.id], this, source, sourceEffect);
+		result = this.battle.singleEvent('Start', status, this.volatiles[status.id], this, source, sourceEffect);
 		if (!result) {
 			// cancel
 			delete this.volatiles[status.id];
@@ -3205,6 +3206,8 @@ var Battle = (function() {
 		return false;
 	};
 	Battle.prototype.runDecision = function(decision) {
+		var pokemon;
+
 		// returns whether or not we ended in a callback
 		switch (decision.choice) {
 		case 'start':
@@ -3220,11 +3223,11 @@ var Battle = (function() {
 				this.switchIn(this.p2.pokemon[pos], pos);
 			}
 			for (var pos=0; pos<this.p1.pokemon.length; pos++) {
-				var pokemon = this.p1.pokemon[pos];
+				pokemon = this.p1.pokemon[pos];
 				this.singleEvent('Start', this.getEffect(pokemon.species), pokemon.speciesData, pokemon);
 			}
 			for (var pos=0; pos<this.p2.pokemon.length; pos++) {
-				var pokemon = this.p2.pokemon[pos];
+				pokemon = this.p2.pokemon[pos];
 				this.singleEvent('Start', this.getEffect(pokemon.species), pokemon.speciesData, pokemon);
 			}
 			this.midTurn = true;
@@ -3272,7 +3275,7 @@ var Battle = (function() {
 			}
 
 			if (i == 0) return;
-			var pokemon = decision.side.pokemon[i];
+			pokemon = decision.side.pokemon[i];
 			if (!pokemon) return;
 			decision.side.pokemon[i] = decision.side.pokemon[0];
 			decision.side.pokemon[0] = pokemon;
diff --git a/config/commands.js b/config/commands.js
index effa1760ad..3d432f0ff0 100644
--- a/config/commands.js
+++ b/config/commands.js
@@ -313,7 +313,7 @@ var commands = exports.commands = {
 
 			if (target === 'all') {
 				if (this.broadcasting) {
-					return this.sendReply('A search with the parameter "all" cannot be broadcast.')
+					return this.sendReply('A search with the parameter "all" cannot be broadcast.');
 				}
 				showAll = true;
 				continue;
diff --git a/crashlogger.js b/crashlogger.js
index dd063fa424..34b9062eff 100644
--- a/crashlogger.js
+++ b/crashlogger.js
@@ -23,7 +23,7 @@ module.exports = (function() {
 			lastCrashLog = datenow;
 			var transport;
 			try {
-				var transport = require('nodemailer').createTransport(
+				transport = require('nodemailer').createTransport(
 					config.crashguardemail.transport,
 					config.crashguardemail.options
 				);
diff --git a/data/formats-data.js b/data/formats-data.js
index e0f462d6f7..1a222843a1 100644
--- a/data/formats-data.js
+++ b/data/formats-data.js
@@ -736,7 +736,7 @@ exports.BattleFormatsData = {
 		tier: "Limbo C"
 	},
 	lickitung: {
-		viableMoves: {"wish":1,"protect":1,"dragontail":1,"curse":1,"bodyslam":1,"return":1,"powerwhip":1,"swordsdance":1,"earthquake":1,"toxic":1,"healbell":1,"earthquake":1},
+		viableMoves: {"wish":1,"protect":1,"dragontail":1,"curse":1,"bodyslam":1,"return":1,"powerwhip":1,"swordsdance":1,"earthquake":1,"toxic":1,"healbell":1},
 		eventPokemon: [
 			{"generation":3,"level":5,"moves":["healbell","wish"]},
 			{"generation":3,"level":38,"moves":["helpinghand","doubleedge","defensecurl","rollout"]}
@@ -1319,7 +1319,7 @@ exports.BattleFormatsData = {
 		tier: "OU"
 	},
 	natu: {
-		viableMoves: {"thunderwave":1,"roost":1,"toxic":1,"reflect":1,"lightscreen":1,"uturn":1,"wish":1,"psychic":1,"nightshade":1,"uturn":1},
+		viableMoves: {"thunderwave":1,"roost":1,"toxic":1,"reflect":1,"lightscreen":1,"uturn":1,"wish":1,"psychic":1,"nightshade":1},
 		eventPokemon: [
 			{"generation":3,"level":22,"moves":["batonpass","futuresight","nightshade","aerialace"]}
 		],
@@ -3591,7 +3591,7 @@ exports.BattleFormatsData = {
 		tier: "Limbo"
 	},
 	dwebble: {
-		viableMoves: {"stealthrock":1,"spikes":1,"shellsmash":1,"earthquake":1,"rockblast":1,"xscissor":1,"stoneedge":1.},
+		viableMoves: {"stealthrock":1,"spikes":1,"shellsmash":1,"earthquake":1,"rockblast":1,"xscissor":1,"stoneedge":1},
 		tier: "LC"
 	},
 	crustle: {
diff --git a/data/items.js b/data/items.js
index fe08336b5a..b30894a675 100644
--- a/data/items.js
+++ b/data/items.js
@@ -1835,7 +1835,7 @@ exports.BattleItems = {
 			pokemon.negateImmunity['Ground'] = true;
 		},
 		onModifySpe: function(speMod) {
-			return this.chain(speMod, .5);
+			return this.chain(speMod, 0.5);
 		},
 		num: 278,
 		gen: 4,
diff --git a/loginserver.js b/loginserver.js
index 0945a71628..2c1dee9fed 100644
--- a/loginserver.js
+++ b/loginserver.js
@@ -85,7 +85,7 @@ module.exports = (function() {
 			res.on('end', function() {
 				var data = null;
 				try {
-					var data = parseJSON(buffer);
+					data = parseJSON(buffer);
 				} catch (e) {}
 				callback(data, res.statusCode);
 				this.openRequests--;
@@ -184,7 +184,7 @@ module.exports = (function() {
 				//console.log('RESPONSE: '+buffer);
 				var data = null;
 				try {
-					var data = parseJSON(buffer);
+					data = parseJSON(buffer);
 				} catch (e) {}
 				for (var i=0,len=requestCallbacks.length; i<len; i++) {
 					if (data) {
diff --git a/rooms.js b/rooms.js
index f6f6d5f693..2cea16f308 100644
--- a/rooms.js
+++ b/rooms.js
@@ -350,7 +350,7 @@ var GlobalRoom = (function() {
 		return true;
 	};
 	GlobalRoom.prototype.deregisterChatRoom = function(id) {
-		var id = toId(id);
+		id = toId(id);
 		var room = rooms[id];
 		if (!room) return false; // room doesn't exist
 		if (!room.chatRoomData) return false; // room isn't registered
@@ -369,7 +369,7 @@ var GlobalRoom = (function() {
 		return true;
 	};
 	GlobalRoom.prototype.delistChatRoom = function(id) {
-		var id = toId(id);
+		id = toId(id);
 		if (!rooms[id]) return false; // room doesn't exist
 		for (var i=this.chatRooms.length-1; i>=0; i--) {
 			if (id === this.chatRooms[i].id) {
@@ -379,7 +379,7 @@ var GlobalRoom = (function() {
 		}
 	};
 	GlobalRoom.prototype.removeChatRoom = function(id) {
-		var id = toId(id);
+		id = toId(id);
 		var room = rooms[id];
 		if (!room) return false; // room doesn't exist
 		room.destroy();
@@ -620,13 +620,14 @@ var BattleRoom = (function() {
 
 							var oldacre = Math.round(data.p1rating.oldacre);
 							var acre = Math.round(data.p1rating.acre);
-							var reasons = ''+(acre-oldacre)+' for '+(p1score>.99?'winning':(p1score<.01?'losing':'tying'));
+							var reasons = ''+(acre-oldacre)+' for '+(p1score>0.99?'winning':(p1score<0.01?'losing':'tying'));
 							if (reasons.substr(0,1) !== '-') reasons = '+'+reasons;
 							self.addRaw(sanitize(p1)+'\'s rating: '+oldacre+' &rarr; <strong>'+acre+'</strong><br />('+reasons+')');
 
-							var oldacre = Math.round(data.p2rating.oldacre);
-							var acre = Math.round(data.p2rating.acre);
-							var reasons = ''+(acre-oldacre)+' for '+(p1score>.99?'losing':(p1score<.01?'winning':'tying'));
+							oldacre = Math.round(data.p2rating.oldacre);
+							acre = Math.round(data.p2rating.acre);
+							reasons = ''+(acre-oldacre)+' for '+(p1score>0.99?'losing':(p1score<0.01?'winning':'tying'));
+							reasons = ''+(acre-oldacre)+' for '+(p1score>0.99?'losing':(p1score<0.01?'winning':'tying'));
 							if (reasons.substr(0,1) !== '-') reasons = '+'+reasons;
 							self.addRaw(sanitize(p2)+'\'s rating: '+oldacre+' &rarr; <strong>'+acre+'</strong><br />('+reasons+')');
 
@@ -1056,7 +1057,7 @@ var BattleRoom = (function() {
 		this.kickInactiveUpdate();
 	};
 	BattleRoom.prototype.joinBattle = function(user, team) {
-		var slot = undefined;
+		var slot;
 		if (this.rated) {
 			if (this.rated.p1 === user.userid) {
 				slot = 0;
diff --git a/simulator.js b/simulator.js
index 9606b67c7e..b4b685b7c5 100644
--- a/simulator.js
+++ b/simulator.js
@@ -137,6 +137,7 @@ var Simulator = (function(){
 	Simulator.prototype.rqid = '';
 	Simulator.prototype.inactiveQueued = false;
 	Simulator.prototype.receive = function(lines) {
+		var player;
 		ResourceMonitor.activeIp = this.activeIp;
 		switch (lines[1]) {
 		case 'update':
@@ -159,14 +160,14 @@ var Simulator = (function(){
 			break;
 
 		case 'callback':
-			var player = this.getPlayer(lines[2]);
+			player = this.getPlayer(lines[2]);
 			if (player) {
 				player.sendTo(this.id, '|callback|' + lines[3]);
 			}
 			break;
 
 		case 'request':
-			var player = this.getPlayer(lines[2]);
+			player = this.getPlayer(lines[2]);
 			var rqid = lines[3];
 			if (player) {
 				this.requests[player.userid] = lines[4];
diff --git a/team-validator.js b/team-validator.js
index 9409fd6f71..e0549a223b 100644
--- a/team-validator.js
+++ b/team-validator.js
@@ -720,10 +720,11 @@ var Validator = (function() {
 		if (sourcesBefore || lsetData.sourcesBefore) {
 			// having sourcesBefore is the equivalent of having everything before that gen
 			// in sources, so we fill the other array in preparation for intersection
+			var learned;
 			if (sourcesBefore && lsetData.sources) {
 				if (!sources) sources = [];
 				for (var i=0, len=lsetData.sources.length; i<len; i++) {
-					var learned = lsetData.sources[i];
+					learned = lsetData.sources[i];
 					if (parseInt(learned.substr(0,1),10) <= sourcesBefore) {
 						sources.push(learned);
 					}
@@ -733,7 +734,7 @@ var Validator = (function() {
 			if (lsetData.sourcesBefore && sources) {
 				if (!lsetData.sources) lsetData.sources = [];
 				for (var i=0, len=sources.length; i<len; i++) {
-					var learned = sources[i];
+					learned = sources[i];
 					if (parseInt(learned.substr(0,1),10) <= lsetData.sourcesBefore) {
 						lsetData.sources.push(learned);
 					}
diff --git a/tools.js b/tools.js
index 3d5c70d622..bba2cc1bc9 100644
--- a/tools.js
+++ b/tools.js
@@ -467,17 +467,18 @@ module.exports = (function () {
 					banlistTable[subformat.banlist[i]] = subformat.name || true;
 					banlistTable[toId(subformat.banlist[i])] = subformat.name || true;
 
-					var plusPos = subformat.banlist[i].indexOf('+');
+					var plusPos = subformat.banlist[i].indexOf('+'),
+						complexList;
 					if (plusPos && plusPos > 0) {
 						var plusPlusPos = subformat.banlist[i].indexOf('++');
 						if (plusPlusPos && plusPlusPos > 0) {
-							var complexList = subformat.banlist[i].split('++');
+							complexList = subformat.banlist[i].split('++');
 							for (var j=0; j<complexList.length; j++) {
 								complexList[j] = toId(complexList[j]);
 							}
 							format.teamBanTable.push(complexList);
 						} else {
-							var complexList = subformat.banlist[i].split('+');
+							complexList = subformat.banlist[i].split('+');
 							for (var j=0; j<complexList.length; j++) {
 								complexList[j] = toId(complexList[j]);
 							}