Aggro refers to gaining the hostile attention of turrets, minions, or neutral monsters, causing them to target and attack your champion. In League of Legends, aggro applies strictly to PvE units, not enemy players. Understanding how aggro works is important because these units follow specific targeting rules, especially when players cast abilities or approach certain ranges.
Drawing aggro can be useful in controlled situations. For example, a laner may take minion aggro to help push the wave or assist a teammate during a Gank. However, taking aggro unintentionally can be dangerous. Turret shots increase in damage with each hit, making mistimed aggression during a Dive extremely risky. Even minions or jungle monsters can deal significant damage early game if a player mismanages their positioning.
Because aggro affects safety, wave control, and decision making, players who understand when and why units retarget gain a meaningful advantage in laning and early skirmishes.