Unique is a term used to describe an item effect. Stacking items (using more than one of the same item) will not result in multiple applications of the item effects that are labelled as unique.

  • Unique passive effects only apply once from identical items.
  • Unique active effects of identical items do not stack and share the same cooldown.
  • Unique aura effects apply once to yourself and once to allies, so two champions with the same unique aura item will each benefit twice from the aura, but other champions without the item will only be affected once.

For example, Youmuu's Ghostblade item Youmuu's Ghostblade has three parts:

But since the last two effects are unique, two Youmuu's Ghostblades will result in only the stats stacking. In other words, the effects of two items would be:

Notice that despite having two Ghostblades, you will only gain +20 armor penetration. Activating one Ghostblade starts the cooldown of both and the buff will last just as long as having one. However, buying a second Ghostblade while the first is on cooldown will allow you to activate it again. Doing so will reset the cooldown timer on both Ghostblades.

However, you can benefit twice from a unique Aura if your champion and a partner's are carrying the same item, like an Aegis of the Legion item Aegis of the Legion (pre patch 6.2). Teammates that do not have the item will only receive one aura. For example, if you are carrying an Aegis of the Legion item Aegis of the Legion, and an ally is also carrying one, you will receive the buff twice, as long as you remain within range of other Aegis holder. Other teammates not carrying an Aegis will only receive the buff once.

Similarly, most of the time, unique effects from different items do stack. Using our last example, carrying Youmuu's Ghostblade item Youmuu's Ghostblade and Serrated Dirk item Serrated Dirk gives and 20 + 10 armor penetration, even though Serrated Dirk item Serrated Dirk is part of Youmuu's Ghostblade item Youmuu's Ghostblade's recipe.

Unique effects that do not stack: