diff --git a/data/scripts.js b/data/scripts.js
index 78db6cf27b..7527cbf59f 100644
--- a/data/scripts.js
+++ b/data/scripts.js
@@ -592,6 +592,16 @@ exports.BattleScripts = {
 		if (!isValid) selectedAbilities.push(selectedAbility);
 		return isValid;
 	},
+	sampleNoReplace: function (list) {
+		var length = list.length;
+		var index = this.random(length);
+		var element = list[index];
+		for (var nextIndex = index + 1; nextIndex < length; index += 1, nextIndex += 1) {
+			list[index] = list[nextIndex];
+		}
+		list.pop();
+		return element;
+	},
 	hasMegaEvo: function (template) {
 		if (template.otherFormes) {
 			var forme = this.getTemplate(template.otherFormes[0]);
@@ -617,31 +627,36 @@ exports.BattleScripts = {
 		}
 	},
 	randomCCTeam: function (side) {
-		var teamdexno = [];
 		var team = [];
 
-		//pick six random pokmeon--no repeats, even among formes
-		//also need to either normalize for formes or select formes at random
-		//unreleased are okay. No CAP for now, but maybe at some later date
+		var natures = Object.keys(this.data.Natures);
+		var items = Object.keys(this.data.Items);
+
+		var hasDexNumber = {};
+		var formes = [[], [], [], [], [], []];
+
+		// pick six random pokemon--no repeats, even among formes
+		// also need to either normalize for formes or select formes at random
+		// unreleased are okay. No CAP for now, but maybe at some later date
+
+		var num;
 		for (var i = 0; i < 6; i++) {
-			while (true) {
-				var x = Math.floor(Math.random() * 721) + 1;
-				if (teamdexno.indexOf(x) === -1) {
-					teamdexno.push(x);
-					break;
-				}
+			do {
+				num = this.random(721) + 1;
+			} while (num in hasDexNumber);
+			hasDexNumber[num] = i;
+		}
+
+		for (var id in this.data.Pokedex) {
+			if (!(this.data.Pokedex[id].num in hasDexNumber)) continue;
+			var template = this.getTemplate(id);
+			if (template.learnset && template.species !== 'Pichu-Spiky-eared') {
+				formes[hasDexNumber[template.num]].push(template.species);
 			}
 		}
 
 		for (var i = 0; i < 6; i++) {
-			//choose forme
-			var formes = [];
-			for (var j in this.data.Pokedex) {
-				if (this.data.Pokedex[j].num === teamdexno[i] && this.getTemplate(this.data.Pokedex[j].species).learnset && this.data.Pokedex[j].species !== 'Pichu-Spiky-eared') {
-					formes.push(this.data.Pokedex[j].species);
-				}
-			}
-			var poke = formes.sample();
+			var poke = formes[i][this.random(formes[i].length)];
 			var template = this.getTemplate(poke);
 
 			//level balance--calculate directly from stats rather than using some silly lookup table
@@ -682,59 +697,47 @@ exports.BattleScripts = {
 			if (template.abilities['H']) {
 				abilities.push(template.abilities['H']);
 			}
-			var ability = abilities.sample();
+			var ability = abilities[this.random(abilities.length)];
 
 			//random nature
-			var nature = ["Adamant", "Bashful", "Bold", "Brave", "Calm", "Careful", "Docile", "Gentle", "Hardy", "Hasty", "Impish", "Jolly", "Lax", "Lonely", "Mild", "Modest", "Naive", "Naughty", "Quiet", "Quirky", "Rash", "Relaxed", "Sassy", "Serious", "Timid"].sample();
+			var nature = natures[this.random(natures.length)];
 
-			//random item--I guess if it's in items.js, it's okay
-			var item = Object.keys(this.data.Items).sample();
+			//random item
+			var item = '';
 
-			//since we're selecting forme at random, we gotta make sure forme/item combo is correct
 			if (template.requiredItem) {
 				item = template.requiredItem;
+			} else {
+				item = items[this.random(items.length)];
 			}
 			if (this.getItem(item).megaStone) {
 				// we'll exclude mega stones for now
-				item = Object.keys(this.data.Items).sample();
+				item = items[this.random(items.length)];
 			}
-			while ((poke === 'Arceus' && item.indexOf("plate") > -1) || (poke === 'Giratina' && item === 'griseousorb')) {
-				item = Object.keys(this.data.Items).sample();
+			//since we're selecting forme at random, we gotta make sure forme/item combo is correct
+			while (poke === 'Arceus' && item.substr(-5) !== 'plate' || poke === 'Giratina' && item === 'griseousorb') {
+				item = items[this.random(items.length)];
 			}
 
 			//random IVs
-			var ivs = {
-				hp: Math.floor(Math.random() * 32),
-				atk: Math.floor(Math.random() * 32),
-				def: Math.floor(Math.random() * 32),
-				spa: Math.floor(Math.random() * 32),
-				spd: Math.floor(Math.random() * 32),
-				spe: Math.floor(Math.random() * 32)
-			};
+			var ivs = {hp: this.random(32), atk: this.random(32), def: this.random(32), spa: this.random(32), spd: this.random(32), spe: this.random(32)};
 
 			//random EVs
-			var evs = {
-				hp: 0,
-				atk: 0,
-				def: 0,
-				spa: 0,
-				spd: 0,
-				spe: 0
-			};
+			var evs = {hp: 0, atk: 0, def: 0, spa: 0, spd: 0, spe: 0};
 			var s = ["hp", "atk", "def", "spa", "spd", "spe"];
 			var evpool = 510;
 			do {
-				var x = s.sample();
-				var y = Math.floor(Math.random() * Math.min(256 - evs[x], evpool + 1));
+				var x = s[this.random(s.length)];
+				var y = this.random(Math.min(256 - evs[x], evpool + 1));
 				evs[x] += y;
 				evpool -= y;
 			} while (evpool > 0);
 
 			//random happiness--useless, since return/frustration is currently a "cheat"
-			var happiness = Math.floor(Math.random() * 256);
+			var happiness = this.random(256);
 
 			//random shininess?
-			var shiny = (Math.random() * 1024 <= 1);
+			var shiny = !this.random(1024);
 
 			//four random unique moves from movepool. don't worry about "attacking" or "viable"
 			var moves;
@@ -747,7 +750,7 @@ exports.BattleScripts = {
 			if (pool.length <= 4) {
 				moves = pool;
 			} else {
-				moves = pool.sample(4);
+				moves = [this.sampleNoReplace(pool), this.sampleNoReplace(pool), this.sampleNoReplace(pool), this.sampleNoReplace(pool)];
 			}
 
 			team.push({
@@ -769,76 +772,80 @@ exports.BattleScripts = {
 	},
 	randomHackmonsCCTeam: function (side) {
 		var team = [];
-		var teamdexno = [];
-		var items = Object.keys(this.data.Items).randomize();
-		var abilities = Object.keys(this.data.Abilities).exclude('mountaineer', 'rebound', 'persistent').randomize();
-		var moves = Object.keys(this.data.Movedex).exclude(/hiddenpower./, 'struggle', 'paleowave', 'shadowstrike', 'magikarpsrevenge').randomize();
 
-		// Pick six random unique Pokmeon
+		var itemPool = Object.keys(this.data.Items);
+		var abilityPool = Object.keys(this.data.Abilities);
+		var movePool = Object.keys(this.data.Movedex);
+		var naturePool = Object.keys(this.data.Natures);
+
+		var hasDexNumber = {};
+		var formes = [[], [], [], [], [], []];
+
+		// pick six random pokemon--no repeats, even among formes
+		// also need to either normalize for formes or select formes at random
+		// unreleased are okay. No CAP for now, but maybe at some later date
+
+		var num;
 		for (var i = 0; i < 6; i++) {
-			while (true) {
-				var x = Math.floor(Math.random() * 721) + 1;
-				if (teamdexno.indexOf(x) === -1) {
-					teamdexno.push(x);
-					break;
-				}
+			do {
+				num = this.random(721) + 1;
+			} while (num in hasDexNumber);
+			hasDexNumber[num] = i;
+		}
+
+		for (var id in this.data.Pokedex) {
+			if (!(this.data.Pokedex[id].num in hasDexNumber)) continue;
+			var template = this.getTemplate(id);
+			if (template.learnset && template.species !== 'Pichu-Spiky-eared') {
+				formes[hasDexNumber[template.num]].push(template.species);
 			}
 		}
 
 		for (var i = 0; i < 6; i++) {
 			// Choose forme
-			var formes = [];
-			for (var j in this.data.Pokedex) {
-				if (this.data.Pokedex[j].num === teamdexno[i] && this.data.Pokedex[j].species !== 'Pichu-Spiky-eared') {
-					formes.push(this.data.Pokedex[j].species);
-				}
-			}
-			var pokemon = formes.sample();
+			var pokemon = formes[i][this.random(formes[i].length)];
 			var template = this.getTemplate(pokemon);
 
 			// Random unique item
-			var item = items[0];
-			items.shift();
+			var item = '';
+			do {
+				item = this.sampleNoReplace(itemPool);
+			} while (this.data.Items[item].isNonstandard);
+
 			// Genesect forms are a sprite difference based on its Drives
 			if (template.species.substr(0, 9) === 'Genesect-' && item !== toId(template.requiredItem)) pokemon = 'Genesect';
 
 			// Random unique ability
-			var ability = abilities[0];
-			abilities.shift();
+			var ability = '';
+			do {
+				ability = this.sampleNoReplace(abilityPool);
+			} while (this.data.Abilities[ability].isNonstandard);
 
 			// Random unique moves
-			var m = moves.splice(0, 4);
+			var m = [];
+			while (true) {
+				var moveid = this.sampleNoReplace(movePool);
+				if (!this.data.Movedex[moveid].isNonstandard && (moveid === 'hiddenpower' || moveid.substr(0, 11) !== 'hiddenpower')) {
+					if (m.push(moveid) >= 4) break;
+				}
+			}
 
 			// Random EVs
-			var evs = {
-				hp: 0,
-				atk: 0,
-				def: 0,
-				spa: 0,
-				spd: 0,
-				spe: 0
-			};
+			var evs = {hp: 0, atk: 0, def: 0, spa: 0, spd: 0, spe: 0};
 			var s = ['hp', 'atk', 'def', 'spa', 'spd', 'spe'];
 			var evpool = 510;
 			do {
-				var x = s.sample();
-				var y = Math.floor(Math.random() * Math.min(256 - evs[x], evpool + 1));
+				var x = s[this.random(s.length)];
+				var y = this.random(Math.min(256 - evs[x], evpool + 1));
 				evs[x] += y;
 				evpool -= y;
 			} while (evpool > 0);
 
 			// Random IVs
-			var ivs = {
-				hp: Math.floor(Math.random() * 32),
-				atk: Math.floor(Math.random() * 32),
-				def: Math.floor(Math.random() * 32),
-				spa: Math.floor(Math.random() * 32),
-				spd: Math.floor(Math.random() * 32),
-				spe: Math.floor(Math.random() * 32)
-			};
+			var ivs = {hp: this.random(32), atk: this.random(32), def: this.random(32), spa: this.random(32), spd: this.random(32), spe: this.random(32)};
 
 			// Random nature
-			var nature = ['Adamant', 'Bashful', 'Bold', 'Brave', 'Calm', 'Careful', 'Docile', 'Gentle', 'Hardy', 'Hasty', 'Impish', 'Jolly', 'Lax', 'Lonely', 'Mild', 'Modest', 'Naive', 'Naughty', 'Quiet', 'Quirky', 'Rash', 'Relaxed', 'Sassy', 'Serious', 'Timid'].sample();
+			var nature = naturePool[this.random(naturePool.length)];
 
 			// Level balance
 			var mbstmin = 1307;
@@ -862,10 +869,10 @@ exports.BattleScripts = {
 			}
 
 			// Random happiness
-			var happiness = Math.floor(Math.random() * 256);
+			var happiness = this.random(256);
 
 			// Random shininess
-			var shiny = (Math.random() * 1024 <= 1);
+			var shiny = !this.random(1024);
 
 			team.push({
 				name: pokemon,
@@ -900,13 +907,13 @@ exports.BattleScripts = {
 		// Decide if the Pokemon can mega evolve early, so viable moves for the mega can be generated
 		if (!noMega && this.hasMegaEvo(template)) {
 			// If there's more than one mega evolution, randomly pick one
-			template = this.getTemplate(template.otherFormes[(template.otherFormes[1]) ? Math.round(Math.random()) : 0]);
+			template = this.getTemplate(template.otherFormes[this.random(template.otherFormes.length)]);
 		}
-		if (template.otherFormes && this.getTemplate(template.otherFormes[0]).forme === 'Primal' && Math.random() >= 0.5) {
+		if (template.otherFormes && this.getTemplate(template.otherFormes[0]).isPrimal && this.random(2)) {
 			template = this.getTemplate(template.otherFormes[0]);
 		}
 
-		var moveKeys = (template.randomBattleMoves || Object.keys(template.learnset)).randomize();
+		var movePool = (template.randomBattleMoves ? template.randomBattleMoves.slice() : Object.keys(template.learnset));
 		var moves = [];
 		var ability = '';
 		var item = '';
@@ -968,13 +975,11 @@ exports.BattleScripts = {
 
 		var damagingMoves, damagingMoveIndex, hasMove, counter, setupType;
 
-		var j = 0;
 		hasMove = {};
 		do {
 			// Choose next 4 moves from learnset/viable moves and add them to moves list:
-			while (moves.length < 4 && j < moveKeys.length) {
-				var moveid = toId(moveKeys[j]);
-				j++;
+			while (moves.length < 4 && movePool.length) {
+				var moveid = this.sampleNoReplace(movePool);
 				if (moveid.substr(0, 11) === 'hiddenpower') {
 					if (hasMove['hiddenpower']) continue;
 					hasMove['hiddenpower'] = true;
@@ -1342,7 +1347,7 @@ exports.BattleScripts = {
 				}
 
 				// Remove rejected moves from the move list.
-				if (rejected && j < moveKeys.length) {
+				if (rejected && movePool.length) {
 					moves.splice(k, 1);
 					break;
 				}
@@ -1355,11 +1360,11 @@ exports.BattleScripts = {
 					}
 				}
 			}
-			if (j < moveKeys.length && moves.length === 4 && !hasMove['judgment']) {
+			if (movePool.length && moves.length === 4 && !hasMove['judgment']) {
 				// Move post-processing:
 				if (damagingMoves.length === 0) {
 					// A set shouldn't have no attacking moves
-					moves.splice(Math.floor(Math.random() * moves.length), 1);
+					moves.splice(this.random(moves.length), 1);
 				} else if (damagingMoves.length === 1) {
 					// Night Shade, Seismic Toss, etc. don't count:
 					if (!damagingMoves[0].damage) {
@@ -1368,7 +1373,7 @@ exports.BattleScripts = {
 						var replace = false;
 						if (damagingid === 'suckerpunch' || damagingid === 'counter' || damagingid === 'mirrorcoat') {
 							// A player shouldn't be forced to rely upon the opponent attacking them to do damage.
-							if (!hasMove['encore'] && Math.random() * 2 > 1) replace = true;
+							if (!hasMove['encore'] && this.random(2)) replace = true;
 						} else if (damagingid === 'focuspunch') {
 							// Focus Punch is a bad idea without a sub:
 							if (!hasMove['substitute']) replace = true;
@@ -1398,7 +1403,7 @@ exports.BattleScripts = {
 					if (rejectCombo) {
 						if (typeCombo === 'Electric/Ice' || typeCombo === 'Fighting/Ghost') rejectCombo = false;
 					}
-					if (rejectCombo) moves.splice(Math.floor(Math.random() * moves.length), 1);
+					if (rejectCombo) moves.splice(this.random(moves.length), 1);
 				} else {
 					// If you have three or more attacks, and none of them are STAB, reject one of them at random.
 					var isStab = false;
@@ -1408,10 +1413,10 @@ exports.BattleScripts = {
 							break;
 						}
 					}
-					if (!isStab) moves.splice(Math.floor(Math.random() * moves.length), 1);
+					if (!isStab) moves.splice(this.random(moves.length), 1);
 				}
 			}
-		} while (moves.length < 4 && j < moveKeys.length);
+		} while (moves.length < 4 && movePool.length);
 
 		// any moveset modification goes here
 		//moves[0] = 'safeguard';
@@ -1461,9 +1466,9 @@ exports.BattleScripts = {
 		var ability = ability0.name;
 		if (abilities[1]) {
 			if (ability0.rating <= ability1.rating) {
-				if (Math.random() * 2 < 1) ability = ability1.name;
+				if (this.random(2)) ability = ability1.name;
 			} else if (ability0.rating - 0.6 <= ability1.rating) {
-				if (Math.random() * 3 < 1) ability = ability1.name;
+				if (!this.random(3)) ability = ability1.name;
 			}
 
 			var rejectAbility = false;
@@ -1529,7 +1534,7 @@ exports.BattleScripts = {
 			} else if (template.id === 'combee') {
 				// Combee always gets Hustle but its only physical move is Endeavor, which loses accuracy
 				ability = 'Honey Gather';
-			} else if (template.id === 'lopunny' && hasMove['switcheroo'] && Math.random() * 3 > 1) {
+			} else if (template.id === 'lopunny' && hasMove['switcheroo'] && this.random(3)) {
 				ability = 'Klutz';
 			} else if (template.id === 'mawilemega') {
 				// Mega Mawile only needs Intimidate for a starting ability
@@ -1576,10 +1581,10 @@ exports.BattleScripts = {
 			// To perma-taunt a Pokemon by giving it Assault Vest
 			item = 'Assault Vest';
 		} else if (hasMove['trick'] || hasMove['switcheroo']) {
-			var randomNum = Math.random() * 2;
-			if (counter.Physical >= 3 && (template.baseStats.spe >= 95 || randomNum > 1)) {
+			var randomNum = this.random(2);
+			if (counter.Physical >= 3 && (template.baseStats.spe >= 95 || randomNum)) {
 				item = 'Choice Band';
-			} else if (counter.Special >= 3 && (template.baseStats.spe >= 95 || randomNum > 1)) {
+			} else if (counter.Special >= 3 && (template.baseStats.spe >= 95 || randomNum)) {
 				item = 'Choice Specs';
 			} else {
 				item = 'Choice Scarf';
@@ -1653,9 +1658,9 @@ exports.BattleScripts = {
 			// less priority than if you'd had both
 			item = 'Light Clay';
 		} else if (counter.Physical >= 4 && !hasMove['fakeout'] && !hasMove['suckerpunch'] && !hasMove['flamecharge'] && !hasMove['rapidspin']) {
-			item = template.baseStats.spe > 82 && template.baseStats.spe < 109 && !counter['priority'] && Math.random() * 3 > 1 ? 'Choice Scarf' : 'Choice Band';
+			item = template.baseStats.spe > 82 && template.baseStats.spe < 109 && !counter['priority'] && this.random(3) ? 'Choice Scarf' : 'Choice Band';
 		} else if (counter.Special >= 4) {
-			item = template.baseStats.spe > 82 && template.baseStats.spe < 109 && !counter['priority'] && Math.random() * 3 > 1 ? 'Choice Scarf' : 'Choice Specs';
+			item = template.baseStats.spe > 82 && template.baseStats.spe < 109 && !counter['priority'] && this.random(3) ? 'Choice Scarf' : 'Choice Specs';
 		} else if (this.getEffectiveness('Ground', template) >= 2 && !hasType['Poison'] && ability !== 'Levitate' && !hasMove['magnetrise']) {
 			item = 'Air Balloon';
 		} else if ((hasMove['eruption'] || hasMove['waterspout']) && !counter['Status']) {
@@ -1777,24 +1782,27 @@ exports.BattleScripts = {
 			ivs: ivs,
 			item: item,
 			level: level,
-			shiny: (Math.random() * 1024 <= 1)
+			shiny: !this.random(1024)
 		};
 	},
 	randomTeam: function (side) {
-		var keys = [];
 		var pokemonLeft = 0;
 		var pokemon = [];
-		for (var i in this.data.FormatsData) {
-			var template = this.getTemplate(i);
-			if (this.data.FormatsData[i].randomBattleMoves && !this.data.FormatsData[i].isNonstandard && !(template.tier in {'LC':1, 'LC Uber':1, 'NFE':1}) && (template.forme.substr(0, 4) !== 'Mega') && template.forme !== 'Primal') {
-				keys.push(i);
+
+		var excludedTiers = {'LC':1, 'LC Uber':1, 'NFE':1};
+		var allowedNFE = {'Chansey':1, 'Doublade':1, 'Pikachu':1, 'Porygon2':1, 'Scyther':1};
+
+		var pokemonPool = [];
+		for (var id in this.data.FormatsData) {
+			var template = this.getTemplate(id);
+			if (!excludedTiers[template.tier] && !template.isMega && !template.isPrimal && !template.isNonstandard && template.randomBattleMoves) {
+				pokemonPool.push(id);
 			}
 		}
-		keys = keys.randomize();
 
 		// PotD stuff
-		var potd = {};
-		if ('Rule:potd' in this.getBanlistTable(this.getFormat())) {
+		var potd;
+		if (Config.potd && 'Rule:potd' in this.getBanlistTable(this.getFormat())) {
 			potd = this.getTemplate(Config.potd);
 		}
 
@@ -1805,49 +1813,71 @@ exports.BattleScripts = {
 		var puCount = 0;
 		var megaCount = 0;
 
-		for (var i = 0; i < keys.length && pokemonLeft < 6; i++) {
-			var template = this.getTemplate(keys[i]);
-			if (!template || !template.name || !template.types) continue;
-			var tier = template.tier;
-			// PUs/Ubers are limited to 2 but have a 20% chance of being added anyway.
-			if (tier === 'PU' && puCount > 1 && Math.random() * 5 > 1) continue;
-			if (tier === 'Uber' && uberCount > 1 && Math.random() * 5 > 1) continue;
+		while (pokemonPool.length && pokemonLeft < 6) {
+			var template = this.getTemplate(this.sampleNoReplace(pokemonPool));
+			if (!template.exists) continue;
 
-			// CAPs have 20% the normal rate
-			if (tier === 'CAP' && Math.random() * 5 > 1) continue;
-			// Unreleased Pokemon have 20% the normal rate
-			if (tier === 'Unreleased' && Math.random() * 5 > 1) continue;
-			// Arceus formes have 1/18 the normal rate each (so Arceus as a whole has a normal rate)
-			if (keys[i].substr(0, 6) === 'arceus' && Math.random() * 18 > 1) continue;
-			// Basculin formes have 1/2 the normal rate each (so Basculin as a whole has a normal rate)
-			if (keys[i].substr(0, 8) === 'basculin' && Math.random() * 2 > 1) continue;
-			// Genesect formes have 1/5 the normal rate each (so Genesect as a whole has a normal rate)
-			if (keys[i].substr(0, 8) === 'genesect' && Math.random() * 5 > 1) continue;
-			// Gourgeist formes have 1/4 the normal rate each (so Gourgeist as a whole has a normal rate)
-			if (keys[i].substr(0, 9) === 'gourgeist' && Math.random() * 4 > 1) continue;
-			// Cosplay Pikachu formes have 20% the normal rate (1/30 the normal rate each)
-			if (keys[i].substr(0, 7) === 'pikachu' && template.species !== 'Pikachu' && Math.random() * 30 > 1) continue;
-			// Regular Pikachu has 80% the normal rate (so Pikachu as a whole has a normal rate)
-			if (template.species === 'Pikachu' && Math.random() * 5 <= 1) continue;
-			// Not available on XY
+			// Limit to one of each species (Species Clause)
+			if (baseFormes[template.baseSpecies]) continue;
+
+			// Not available on ORAS
 			if (template.species === 'Pichu-Spiky-eared') continue;
+
 			// Only certain NFE Pokemon are allowed
-			if (template.evos.length && !(template.species in {'Chansey':1, 'Doublade':1, 'Pikachu':1, 'Porygon2':1, 'Scyther':1})) continue;
+			if (template.evos.length && !allowedNFE[template.species]) continue;
+
+			var tier = template.tier;
+			switch (tier) {
+			case 'PU':
+				// PUs are limited to 2 but have a 20% chance of being added anyway.
+				if (puCount > 1 && this.random(5) >= 1) continue;
+				break;
+			case 'Uber':
+				// Ubers are limited to 2 but have a 20% chance of being added anyway.
+				if (uberCount > 1 && this.random(5) >= 1) continue;
+				break;
+			case 'CAP':
+				// CAPs have 20% the normal rate
+				if (this.random(5) >= 1) continue;
+				break;
+			case 'Unreleased':
+				// Unreleased Pokémon have 20% the normal rate
+				if (this.random(5) >= 1) continue;
+			}
+
+			// Adjust rate for species with multiple formes
+			switch (template.baseSpecies) {
+			case 'Arceus':
+				if (this.random(18) >= 1) continue;
+				break;
+			case 'Basculin':
+				if (this.random(2) >= 1) continue;
+				break;
+			case 'Genesect':
+				if (this.random(5) >= 1) continue;
+				break;
+			case 'Gourgeist':
+				if (this.random(4) >= 1) continue;
+				break;
+			case 'Pikachu':
+				// Cosplay Pikachu formes have 20% the normal rate (1/30 the normal rate each)
+				if (template.species !== 'Pikachu' && this.random(30) >= 1) continue;
+			}
 
 			// Limit 2 of any type
 			var types = template.types;
 			var skip = false;
 			for (var t = 0; t < types.length; t++) {
-				if (typeCount[types[t]] > 1 && Math.random() * 5 > 1) {
+				if (typeCount[types[t]] > 1 && this.random(5) >= 1) {
 					skip = true;
 					break;
 				}
 			}
 			if (skip) continue;
 
-			if (potd && potd.name && potd.types) {
+			if (potd && potd.exists) {
 				// The Pokemon of the Day belongs in slot 2
-				if (i === 1) {
+				if (pokemon.length === 1) {
 					template = potd;
 					if (template.species === 'Magikarp') {
 						template.randomBattleMoves = ['magikarpsrevenge', 'splash', 'bounce'];
@@ -1859,7 +1889,7 @@ exports.BattleScripts = {
 				}
 			}
 
-			var set = this.randomSet(template, i, megaCount);
+			var set = this.randomSet(template, pokemon.length, megaCount);
 
 			// Illusion shouldn't be on the last pokemon of the team
 			if (set.ability === 'Illusion' && pokemonLeft > 4) continue;
@@ -1872,20 +1902,18 @@ exports.BattleScripts = {
 			}
 			if (typeCombo in typeComboCount) continue;
 
-			// Limit the number of Megas to one, just like in-game
-			var forme = template.otherFormes ? this.getTemplate(template.otherFormes[0]) : 0;
+			// Limit the number of Megas to one
+			var forme = template.otherFormes && this.getTemplate(template.otherFormes[0]);
 			var isMegaSet = this.getItem(set.item).megaStone || (forme && forme.isMega && forme.requiredMove && set.moves.indexOf(toId(forme.requiredMove)) >= 0);
 			if (isMegaSet && megaCount > 0) continue;
 
-			// Limit to one of each species (Species Clause)
-			if (baseFormes[template.baseSpecies]) continue;
-			baseFormes[template.baseSpecies] = 1;
-
 			// Okay, the set passes, add it to our team
 			pokemon.push(set);
 
+			// Now that our Pokemon has passed all checks, we can increment our counters
 			pokemonLeft++;
-			// Now that our Pokemon has passed all checks, we can increment the type counter
+
+			// Increment type counters
 			for (var t = 0; t < types.length; t++) {
 				if (types[t] in typeCount) {
 					typeCount[types[t]]++;
@@ -1895,84 +1923,114 @@ exports.BattleScripts = {
 			}
 			typeComboCount[typeCombo] = 1;
 
-			// Increment Uber/NU and mega counter
+			// Increment Uber/NU counters
 			if (tier === 'Uber') {
 				uberCount++;
 			} else if (tier === 'PU') {
 				puCount++;
 			}
+
+			// Increment mega and base species counters
 			if (isMegaSet) megaCount++;
+			baseFormes[template.baseSpecies] = 1;
 		}
 		return pokemon;
 	},
 	randomDoublesTeam: function (side) {
-		var keys = [];
 		var pokemonLeft = 0;
 		var pokemon = [];
-		for (var i in this.data.FormatsData) {
-			var template = this.getTemplate(i);
-			if (this.data.FormatsData[i].randomBattleMoves && !this.data.FormatsData[i].isNonstandard && !(template.tier in {'LC':1, 'LC Uber':1, 'NFE':1}) && (template.forme.substr(0, 4) !== 'Mega') && template.forme !== 'Primal') {
-				keys.push(i);
+
+		var excludedTiers = {'LC':1, 'LC Uber':1, 'NFE':1};
+		var allowedNFE = {'Chansey':1, 'Doublade':1, 'Pikachu':1, 'Porygon2':1, 'Scyther':1};
+
+		var pokemonPool = [];
+		for (var id in this.data.FormatsData) {
+			var template = this.getTemplate(id);
+			if (!excludedTiers[template.tier] && !template.isMega && !template.isPrimal && !template.isNonstandard && template.randomBattleMoves) {
+				pokemonPool.push(id);
 			}
 		}
-		keys = keys.randomize();
 
 		// PotD stuff
-		var potd = {};
-		if ('Rule:potd' in this.getBanlistTable(this.getFormat())) {
+		var potd;
+		if (Config.potd && 'Rule:potd' in this.getBanlistTable(this.getFormat())) {
 			potd = this.getTemplate(Config.potd);
 		}
 
 		var typeCount = {};
 		var typeComboCount = {};
 		var baseFormes = {};
+		var uberCount = 0;
+		var puCount = 0;
 		var megaCount = 0;
 
-		for (var i = 0; i < keys.length && pokemonLeft < 6; i++) {
-			var template = this.getTemplate(keys[i]);
-			if (!template || !template.name || !template.types) continue;
-			var tier = template.tier;
-			// Unreleased Pokemon have 20% the normal rate
-			if (tier === 'Unreleased' && Math.random() * 5 > 1) continue;
-			// Arceus formes have 1/18 the normal rate each (so Arceus as a whole has a normal rate)
-			if (keys[i].substr(0, 6) === 'arceus' && Math.random() * 18 > 1) continue;
-			// Basculin formes have 1/2 the normal rate each (so Basculin as a whole has a normal rate)
-			if (keys[i].substr(0, 8) === 'basculin' && Math.random() * 2 > 1) continue;
-			// Genesect formes have 1/5 the normal rate each (so Genesect as a whole has a normal rate)
-			if (keys[i].substr(0, 8) === 'genesect' && Math.random() * 5 > 1) continue;
-			// Gourgeist formes have 1/4 the normal rate each (so Gourgeist as a whole has a normal rate)
-			if (keys[i].substr(0, 9) === 'gourgeist' && Math.random() * 4 > 1) continue;
-			// Cosplay Pikachu formes have 20% the normal rate (1/30 the normal rate each)
-			if (keys[i].substr(0, 7) === 'pikachu' && template.species !== 'Pikachu' && Math.random() * 30 > 1) continue;
-			// Regular Pikachu has 80% the normal rate (so Pikachu as a whole has a normal rate)
-			if (template.species === 'Pikachu' && Math.random() * 5 <= 1) continue;
-			// Not available on XY
+		while (pokemonPool.length && pokemonLeft < 6) {
+			var template = this.getTemplate(this.sampleNoReplace(pokemonPool));
+			if (!template.exists) continue;
+
+			// Limit to one of each species (Species Clause)
+			if (baseFormes[template.baseSpecies]) continue;
+
+			// Not available on ORAS
 			if (template.species === 'Pichu-Spiky-eared') continue;
+
 			// Only certain NFE Pokemon are allowed
-			if (template.evos.length && !(template.species in {'Chansey':1, 'Doublade':1, 'Pikachu':1, 'Porygon2':1, 'Scyther':1})) continue;
+			if (template.evos.length && !allowedNFE[template.species]) continue;
+
+			var tier = template.tier;
+			switch (tier) {
+			case 'CAP':
+				// CAPs have 20% the normal rate
+				if (this.random(5) >= 1) continue;
+				break;
+			case 'Unreleased':
+				// Unreleased Pokémon have 20% the normal rate
+				if (this.random(5) >= 1) continue;
+			}
+
+			// Adjust rate for species with multiple formes
+			switch (template.baseSpecies) {
+			case 'Arceus':
+				if (this.random(18) >= 1) continue;
+				break;
+			case 'Basculin':
+				if (this.random(2) >= 1) continue;
+				break;
+			case 'Genesect':
+				if (this.random(5) >= 1) continue;
+				break;
+			case 'Gourgeist':
+				if (this.random(4) >= 1) continue;
+				break;
+			case 'Pikachu':
+				// Cosplay Pikachu formes have 20% the normal rate (1/30 the normal rate each)
+				if (template.species !== 'Pikachu' && this.random(30) >= 1) continue;
+			}
 
 			// Limit 2 of any type
 			var types = template.types;
 			var skip = false;
 			for (var t = 0; t < types.length; t++) {
-				if (typeCount[types[t]] > 1 && Math.random() * 5 > 1) {
+				if (typeCount[types[t]] > 1 && this.random(5) >= 1) {
 					skip = true;
 					break;
 				}
 			}
 			if (skip) continue;
 
-			// More potd stuff
-			if (potd && potd.name && potd.types) {
+			if (potd && potd.exists) {
 				// The Pokemon of the Day belongs in slot 3
-				if (i === 2) {
+				if (pokemon.length === 2) {
 					template = potd;
 				} else if (template.species === potd.species) {
 					continue; // No, thanks, I've already got one
 				}
 			}
 
-			var set = this.randomDoublesSet(template, megaCount);
+			var set = this.randomDoublesSet(template, pokemon.length, megaCount);
+
+			// Illusion shouldn't be on the last pokemon of the team
+			if (set.ability === 'Illusion' && pokemonLeft > 4) continue;
 
 			// Limit 1 of any type combination
 			var typeCombo = types.join();
@@ -1982,20 +2040,18 @@ exports.BattleScripts = {
 			}
 			if (typeCombo in typeComboCount) continue;
 
-			// Limit the number of Megas to one, just like in-game
-			var forme = template.otherFormes ? this.getTemplate(template.otherFormes[0]) : 0;
+			// Limit the number of Megas to one
+			var forme = template.otherFormes && this.getTemplate(template.otherFormes[0]);
 			var isMegaSet = this.getItem(set.item).megaStone || (forme && forme.isMega && forme.requiredMove && set.moves.indexOf(toId(forme.requiredMove)) >= 0);
 			if (isMegaSet && megaCount > 0) continue;
 
-			// Limit to one of each species (Species Clause)
-			if (baseFormes[template.baseSpecies]) continue;
-			baseFormes[template.baseSpecies] = 1;
-
 			// Okay, the set passes, add it to our team
 			pokemon.push(set);
 
+			// Now that our Pokemon has passed all checks, we can increment our counters
 			pokemonLeft++;
-			// Now that our Pokemon has passed all checks, we can increment the type counter
+
+			// Increment type counters
 			for (var t = 0; t < types.length; t++) {
 				if (types[t] in typeCount) {
 					typeCount[types[t]]++;
@@ -2005,8 +2061,16 @@ exports.BattleScripts = {
 			}
 			typeComboCount[typeCombo] = 1;
 
-			// Increment mega counter
+			// Increment Uber/NU counters
+			if (tier === 'Uber') {
+				uberCount++;
+			} else if (tier === 'PU') {
+				puCount++;
+			}
+
+			// Increment mega and base species counters
 			if (isMegaSet) megaCount++;
+			baseFormes[template.baseSpecies] = 1;
 		}
 		return pokemon;
 	},
@@ -2025,13 +2089,15 @@ exports.BattleScripts = {
 		// Decide if the Pokemon can mega evolve early, so viable moves for the mega can be generated
 		if (!noMega && this.hasMegaEvo(template)) {
 			// If there's more than one mega evolution, randomly pick one
-			template = this.getTemplate(template.otherFormes[(template.otherFormes[1]) ? Math.round(Math.random()) : 0]);
+			template = this.getTemplate(template.otherFormes[this.random(template.otherFormes.length)]);
 		}
-		if (template.otherFormes && this.getTemplate(template.otherFormes[0]).forme === 'Primal' && Math.random() >= 0.5) {
+		if (template.otherFormes && this.getTemplate(template.otherFormes[0]).isPrimal && this.random(2)) {
 			template = this.getTemplate(template.otherFormes[0]);
 		}
 
-		var moveKeys = (template.randomDoubleBattleMoves || template.randomBattleMoves || Object.keys(template.learnset)).randomize();
+		var movePool = (template.randomDoubleBattleMoves || template.randomBattleMoves);
+		movePool = movePool ? movePool.slice() : Object.keys(template.learnset);
+
 		var moves = [];
 		var ability = '';
 		var item = '';
@@ -2090,12 +2156,10 @@ exports.BattleScripts = {
 		var damagingMoves, damagingMoveIndex, hasMove, counter, setupType;
 
 		hasMove = {};
-		var j = 0;
 		do {
 			// Choose next 4 moves from learnset/viable moves and add them to moves list:
-			while (moves.length < 4 && j < moveKeys.length) {
-				var moveid = toId(moveKeys[j]);
-				j++;
+			while (moves.length < 4 && movePool.length) {
+				var moveid = toId(this.sampleNoReplace(movePool));
 				if (moveid.substr(0, 11) === 'hiddenpower') {
 					if (hasMove['hiddenpower']) continue;
 					hasMove['hiddenpower'] = true;
@@ -2429,7 +2493,7 @@ exports.BattleScripts = {
 				}
 
 				// Remove rejected moves from the move list.
-				if (rejected && j < moveKeys.length) {
+				if (rejected && movePool.length) {
 					moves.splice(k, 1);
 					break;
 				}
@@ -2442,11 +2506,11 @@ exports.BattleScripts = {
 					}
 				}
 			}
-			if (j < moveKeys.length && moves.length === 4 && !hasMove['judgment']) {
+			if (movePool.length && moves.length === 4 && !hasMove['judgment']) {
 				// Move post-processing:
 				if (damagingMoves.length === 0) {
 					// A set shouldn't have no attacking moves
-					moves.splice(Math.floor(Math.random() * moves.length), 1);
+					moves.splice(this.random(moves.length), 1);
 				} else if (damagingMoves.length === 1) {
 					// Night Shade, Seismic Toss, etc. don't count:
 					if (!damagingMoves[0].damage) {
@@ -2455,7 +2519,7 @@ exports.BattleScripts = {
 						var replace = false;
 						if (damagingid === 'suckerpunch' || damagingid === 'counter' || damagingid === 'mirrorcoat') {
 							// A player shouldn't be forced to rely upon the opponent attacking them to do damage.
-							if (!hasMove['encore'] && Math.random() * 2 > 1) replace = true;
+							if (!hasMove['encore'] && this.random(2)) replace = true;
 						} else if (damagingid === 'focuspunch') {
 							// Focus Punch is a bad idea without a sub:
 							if (!hasMove['substitute']) replace = true;
@@ -2485,7 +2549,7 @@ exports.BattleScripts = {
 					if (rejectCombo) {
 						if (typeCombo === 'Electric/Ice' || typeCombo === 'Fighting/Ghost') rejectCombo = false;
 					}
-					if (rejectCombo) moves.splice(Math.floor(Math.random() * moves.length), 1);
+					if (rejectCombo) moves.splice(this.random(moves.length), 1);
 				} else {
 					// If you have three or more attacks, and none of them are STAB, reject one of them at random.
 					var isStab = false;
@@ -2495,10 +2559,10 @@ exports.BattleScripts = {
 							break;
 						}
 					}
-					if (!isStab) moves.splice(Math.floor(Math.random() * moves.length), 1);
+					if (!isStab) moves.splice(this.random(moves.length), 1);
 				}
 			}
-		} while (moves.length < 4 && j < moveKeys.length);
+		} while (moves.length < 4 && movePool.length);
 
 		// If Hidden Power has been removed, reset the IVs
 		if (!hasMove['hiddenpower']) {
@@ -2520,9 +2584,9 @@ exports.BattleScripts = {
 		var ability = ability0.name;
 		if (abilities[1]) {
 			if (ability0.rating <= ability1.rating) {
-				if (Math.random() * 2 < 1) ability = ability1.name;
+				if (this.random(2)) ability = ability1.name;
 			} else if (ability0.rating - 0.6 <= ability1.rating) {
-				if (Math.random() * 3 < 1) ability = ability1.name;
+				if (!this.random(3)) ability = ability1.name;
 			}
 
 			var rejectAbility = false;
@@ -2628,10 +2692,10 @@ exports.BattleScripts = {
 		} else if (hasMove['trick'] && hasMove['gyroball']) {
 			item = 'Iron Ball';
 		} else if (hasMove['trick'] || hasMove['switcheroo']) {
-			var randomNum = Math.random() * 2;
-			if (counter.Physical >= 3 && (template.baseStats.spe >= 95 || randomNum > 1)) {
+			var randomNum = this.random(2);
+			if (counter.Physical >= 3 && (template.baseStats.spe >= 95 || randomNum)) {
 				item = 'Choice Band';
-			} else if (counter.Special >= 3 && (template.baseStats.spe >= 95 || randomNum > 1)) {
+			} else if (counter.Special >= 3 && (template.baseStats.spe >= 95 || randomNum)) {
 				item = 'Choice Specs';
 			} else {
 				item = 'Choice Scarf';
@@ -2769,7 +2833,7 @@ exports.BattleScripts = {
 			ivs: ivs,
 			item: item,
 			level: level,
-			shiny: (Math.random() * (template.id === 'missingno' ? 4 : 1024) <= 1)
+			shiny: !this.random(template.id === 'missingno' ? 4 : 1024)
 		};
 	},
 	randomSeasonalMulanTeam: function (side) {