Stacking can refer to a number of situations.
Inventory stacking[]
Many items, such as crafting materials, will stack with other items of the same type in the one slot with a number to indicate the count. The maximum number of items that a stack can contain is 250, and this is the amount players usually refer to when describing a "stack" of a particular item.
Some items do not stack, such as all weapons, most Quest items, and many Salvage Items. Two such items will not stack in the same slot even if they have identical statistics. Collectable drops always stack.
Stacks can be split. Hold down the Shift key while dragging a stack and a dialog will pop up. The number entered into this dialog will be the number of items taken out of the original stack and placed in the destination stack.
Effects stacking[]
Stacking refer to effects of different skills and conditions adding up together. For example, a player could cast one spell to give +3 pips of health regeneration and then cast another spell to give an additional +2 health regeneration levels so they stack to +5. Such effects will not exceed the maximum of 10 pips degen/regen. Some effects, like slowing effects and bonuses from runes, do not stack, and only the most powerful effect is taken in to account. Multiple copies of the same skill and Conditions of the same type do not stack. Benefits from spells that target enemies but also benefit the caster can be stacked; a Necromancer casting Life Siphon on two foes will receive twice the health regeneration. Also note that effects going past the cap on their own, such as Dash for movement speed increase or Mind Freeze for decrease, will not be capped. Below is a table of all effect caps.
| Property | Positive | Negative |
|---|---|---|
| Attack speed | +33% | -50% |
| Movement speed | +33% | -50% |
| Healing modification | none | -40% |
| Adrenaline modification | +100% | none |
| Recharge modification | -50% | none |
| Health or energy regeneration | +10 | -10 |
| Activation modification | -25% | +150% |
| Armor | +25 | none |
| Attribute | 20 (211) | 0 |
- 1 21 can only be achieved with an "Item's attribute +1 while using skills" Inscription.
- The maximum number of maintained enchantments is equal to the number of energy regeneration pips you have up to -10 energy regeneration. For instance, if you have +4 natural energy regeneration, you are able to maintain 14 enchantments.
Rune stacking[]
The stackability of runes is discussed in the Rune article.