First Lua

local ToySkull = RegisterMod("ToySkull", 1)
local game = Game()

--reference item & costume

CollectibleType.COLLECTIBLE_TOY_SKULL = Isaac.GetItemIdByName("Toy Skull")
ToySkull.COSTUME_TOY_SKULL = Isaac.GetCostumeIdByPath("gfx/characters/toyskull.anm2")

local ToyBonus = {
	TOYSKULL = 2  --Luck
}

--Shell Game tables

local Grab = {
	Coin = nil,
	Key = nil,
	Bomb = nil
}
local Shell = {
	Traget = nil,
	RADIUS = 4
}

local pickup = {}

--update the inventory

local function UpdateToy(player)
	HasToy.ToySkull = player:HasCollectible(CollectibleType.COLLECTIBLE_TOY_SKULL)
end

--if you start a run or continue. Before anything happens

function ToySkull:onPlayerInit(player)
	UpdateToy(player)
end
ToySkull:AddCallback(ModCallbacks.MC_POST_PLAYER_INIT, ToySkull.onPlayerInit)

--when passive effects should update

function ToySkull:onUpdate(player)
	if game:GetFrameCount() == 1 then
		ToySkull.HasToySkull = false
	--spawn in if necessary
	end
	if not ToySkull.HasToySkull and HasToy.ToySkull then
		player:AddNullCostume(ToySkull.COSTUME_TOY_SKULL)
		ToySkull.HasToySkull = true
	end
	UpdateToy(player)
end
ToySkull:AddCallback(Modcallbacks.MC_POST_PEFFECT_UPDATE, ToySkull.onUpdate)

--update the cache

function ToySkull:onCache(player, cacheFlag)
	if cacheFlag == CacheFlag.CACHE_LUCK then
		if player:HasCollectible(CollectibleType.COLLECTIBLE_TOY_SKULL) and not HasToy.ToySkull then
			player.Luck = player.Luck + ToyBonus.ToySkull
		end
	end
end
ToySkull:AddCallback(ModCallbacks.MC_EVALUATE_CACHE, ToySkull.onCache)

--add Shell Game functionality

function ToySkull.onPayout()

	--is there a Shell Game Beggar in the room?

	if HasToy.ToySkull and Shell.Target == nil then
		local roomEntities = Isaac.GetRoomEntities()
		local shellGame = Isaac:GetEntityVariantByName("Shell Game Beggar")
		for i, entity in pairs(roomEntities) do
			if entity.Type == EntityType.ENTITY_SLOT
			   and entity.Variant == shellGame then
			   Shell.Target = entity
			end
		end

	--if yes, then the game will check if he spawns a pickup. In this case a coin

	elseif Shell.Target.Spawn(EntityType.ENTITY_PICKUP)
	       and pickup.Variant == PickupVariant.PICKUP_COIN
	       and pickup.Subtype == CoinSubType.COIN_PENNY then
			local shellEntities = Isaac.FindInRadius(Shell.Target.Position, 100, EntityPartition.PICKUP)
			for j, grabc in pairs(shellEntities) do
				if grabc.Variant == PickupVariant.PICKUP_COIN
				   and grabc.Subtype == CoinSubType.COIN_PENNY then
				   Grab.Coin = grabc
				   Isaac.Spawn(
					       EntityType.ENTITY_PICKUP,
				 	       PickupVariant.PICKUP_GRAB_BAG,
					       Grab.Coin.Position,
					       Vector(
						       math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS,
						       math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS
					        ),
					       Shell.Target
				    )
				   Grab.Coin:Remove()
				   Grab.Coin = nil
				end
			end
			Shell.Target = nil

	--now a doublecoin

	elseif Shell.Target.Spawn(EntityType.ENTITY_PICKUP)
	       and pickup.Variant == PickupVariant.PICKUP_COIN
	       and pickup.Subtype == CoinSubType.COIN_DOUBLEPACK then
			local shellEntities = Isaac.FindInRadius(Shell.Target.Position, 100, EntityPartition.PICKUP)
			for k, grabc in pairs(shellEntities) do
				if grabc.Variant == PickupVariant.PICKUP_COIN
				   and grabc.Subtype == CoinSubType.COIN_DOUBLEPACK then
				   Grab.Coin = grabc
				   Isaac.Spawn(
					       EntityType.ENTITY_PICKUP,
				 	       PickupVariant.PICKUP_GRAB_BAG,
					       Grab.Coin.Position,
					       Vector(
						       math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS,
						       math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS
					        ),
					       Shell.Target
				    )
				   Grab.Coin:Remove()
				   Grab.Coin = nil
				end
			end
			Shell.Target = nil


	--now a key

	elseif Shell.Target.Spawn(EntityType.ENTITY_PICKUP)
	       and pickup.Variant == PickupVariant.PICKUP_KEY
	       and pickup.Subtype == KeySubType.KEY_NORMAL then
			local shellEntities = Isaac.FindInRadius(Shell.Target.Position, 100, EntityPartition.PICKUP)
			for l, grabk in pairs(shellEntities) do
				if grabk.Variant == PickupVariant.PICKUP_KEY
				   and grabk.Subtype == KeySubType.KEY_NORMAL then
				   Grab.Key = grabk
				   Isaac.Spawn(
					       EntityType.ENTITY_PICKUP,
				 	       PickupVariant.PICKUP_PILL,
					       Grab.Key.Position,
					       Vector(
						       math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS,
						       math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS
					        ),
					       Shell.Target
				    )
				   Grab.Key:Remove()
				   Grab.Key = nil
				end
			end
			Shell.Target = nil

	--now a doublekey

	elseif Shell.Target.Spawn(EntityType.ENTITY_PICKUP)
	       and pickup.Variant == PickupVariant.PICKUP_KEY
	       and pickup.Subtype == KeySubType.KEY_DOUBLEPACK then
			local shellEntities = Isaac.FindInRadius(Shell.Target.Position, 100, EntityPartition.PICKUP)
			for m, grabk in pairs(shellEntities) do
				if grabk.Variant == PickupVariant.PICKUP_KEY
				   and grabk.Subtype == KeySubType.KEY_DOUBLEPACK then
				   Grab.Key = grabk
				   Isaac.Spawn(
					       EntityType.ENTITY_PICKUP,
				 	       PickupVariant.PICKUP_PILL,
					       Grab.Key.Position,
					       Vector(
						       math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS,
						       math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS
					        ),
					       Shell.Target
				    )
				   Grab.Key:Remove()
				   Grab.Key = nil
				end
			end
			Shell.Target = nil

	--now a bomb

	elseif Shell.Target.Spawn(EntityType.ENTITY_PICKUP)
	       and pickup.Variant == PickupVariant.PICKUP_BOMB
	       and pickup.Subtype == BombSubType.BOMB_NORMAL then
			local shellEntities = Isaac.FindInRadius(Shell.Target.Position, 100, EntityPartition.PICKUP)
			for n, grabbo in pairs(shellEntities) do
				if grabbo.Variant == PickupVariant.PICKUP_BOMB
				   and grabbo.Subtype == BombSubType.BOMB_NORMAL then
					Grab.Bomb = grabbo
				   	local rng = player:GetCollectibleRNG(CollectibleType.COLLECTIBLE_TOY_SKULL)
					local roll = rng:RandomInit(20)
					if roll < 2 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_HAGALAZ, Grab.Bomb.Position, Vector							            (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					esleif roll < 4 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_JERA, Grab.Bomb.Position, Vector							    		    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							     			     Shell.RADIUS), Shell.Target)
					elseif roll < 6 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_EHWAZ, Grab.Bomb.Position, Vector							                    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					elseif roll < 8 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_DAGAZ, Grab.Bomb.Position, Vector							                    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					elseif roll < 10 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_ANSUZ, Grab.Bomb.Position, Vector							                    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					elseif roll < 12 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_PERTHRO, Grab.Bomb.Position, Vector							            (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					esleif roll < 14 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_BERKANO, Grab.Bomb.Position, Vector							    		    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							     			     Shell.RADIUS), Shell.Target)
					elseif roll < 16 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_ALGIZ, Grab.Bomb.Position, Vector							                    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					elseif roll < 18 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_BLANK, Grab.Bomb.Position, Vector							                    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					else Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_BLACK, Grab.Bomb.Position, Vector							                    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					end
				  	Grab.Bomb:Remove()
				 	Grab.Bomb = nil
				end
			end
			Shell.Target = nil

	--now a doublebomb

	elseif Shell.Target.Spawn(EntityType.ENTITY_PICKUP)
	       and pickup.Variant == PickupVariant.PICKUP_BOMB
	       and pickup.Subtype == BombSubType.BOMB_DOUBLEPACK then
			local shellEntities = Isaac.FindInRadius(Shell.Target.Position, 100, EntityPartition.PICKUP)
			for o, grabbo in pairs(shellEntities) do
				if grabbo.Variant == PickupVariant.PICKUP_BOMB
				   and grabbo.Subtype == BombSubType.BOMB_DOUBLEPACK then
					Grab.Bomb = grabbo
				   	local rng = player:GetCollectibleRNG(CollectibleType.COLLECTIBLE_TOY_SKULL)
					local roll = rng:RandomInit(20)
					if roll < 2 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_HAGALAZ, Grab.Bomb.Position, Vector							            (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					esleif roll < 4 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_JERA, Grab.Bomb.Position, Vector							    		    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							     			     Shell.RADIUS), Shell.Target)
					elseif roll < 6 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_EHWAZ, Grab.Bomb.Position, Vector							                    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					elseif roll < 8 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_DAGAZ, Grab.Bomb.Position, Vector							                    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					elseif roll < 10 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_ANSUZ, Grab.Bomb.Position, Vector							                    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					elseif roll < 12 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_PERTHRO, Grab.Bomb.Position, Vector							            (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					esleif roll < 14 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_BERKANO, Grab.Bomb.Position, Vector							    	    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							     			     Shell.RADIUS), Shell.Target)
					elseif roll < 16 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_ALGIZ, Grab.Bomb.Position, Vector							                    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					elseif roll < 18 then
				   		Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_BLANK, Grab.Bomb.Position, Vector							                    (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                             Shell.RADIUS), Shell.Target)
					else Isaac.Spawn(EntityType.ENTITY_PICKUP, PickupVariant.PICKUP_TAROTCARD, CARD_RUNE_BLACK, Grab.Bomb.Position, Vector							                 (math.random(Shell.RADIUS * 2 + 1) - Shell.RADIUS, math.random(Shell.RADIUS * 2 + 1) - 							                          Shell.RADIUS), Shell.Target)
					end
				  	Grab.Bomb:Remove()
				 	Grab.Bomb = nil
				end
			end
			Shell.Target = nil
	end
end
ToySkull:AddCallback(ModCallbacks.MC_POST_NPC_UPDATE, ToySkull.onPayout)