|This article is about an older version of DF.
(Are you looking for information about pump stacks?)
Some items can be stacked in order to take up less room. Items like crossbow bolts, coins, and bones are examples of stacks of solid objects. Booze is the most often encountered stack of a liquid item.
It's not possible to combine different items of the same type into stacks. For example, if you have two stacks of plump helmets, each with a count of two, it's not possible to combine them into a single stack of four plump helmets. Also, if you fire a single arrow from a stack of 30 arrows, you won't be able to put the fired arrow back into the original stack, and you'll eventually end up with 30 stacks of arrows, each containing just a single arrow. The closest thing the game has to combining stacks is cooking meals: if you cook a lavish meal out of four stacks of food, each of size five, you'll end up with a single stack of twenty meals.
Stacks of items are visible as an item name with a number in brackets next to it. For example, "Iron bolts" is a stack of 20 iron crossbow bolts. A dwarf can pick up the entire stack and carry it, or a marksdwarf can remove a single bolt from the stack and fire it.
For stacks of food or booze, a dwarf will eat or drink a single unit of food or booze at a sitting. The size of the stack does not affect how much the dwarf will consume.