What is Denying?

Denying is a mechanic that allows you to kill your allied units (creeps, heroes, or towers) to prevent the enemy from gaining gold and experience. An allied hero can only be denied if they have negative effects and less than 25% HP. For creeps, non-heroes, and illusions, this threshold is 50% of full HP, and for towers, it is 10%. Deny is used to control the lane, slow down the opponent's progress, and reduce their farm.

Previously, creep denies completely denied experience to the enemy, but in recent patches, they grant partial experience — though the mechanic remains a crucial part of micro-control.