I have several questions...
1. What does those 2 ints and the boolean in mergeItemStack(ItemStack, int, int, boolean) mean?
2. Is it possible to shift player inventory slot IDs up and down? (I know it cant go below 0)
3. What is the range of player inventory slot IDs?
You can just reply on 1 question, that will be fine.
I am currently learning to make Gui and stuff.