Creep Stacking is the process of drawing neutral creeps away from their camps in order to increase the number of units in an area. Generally, neutral creeps will spawn in the first 30 seconds of the game and at every minute thereafter. However, new creeps cannot spawn if a unit such as a player or a ward is present. By pulling neutral creeps beyond their camp boundaries, the game will generate a new set of creeps for the player to interact with in addition to any remaining creeps. This is incredibly time efficient, since it effectively increases the amount of gold available for a team. In many cases, a support who has stacked a substantial amount of creeps can build a sizable chunk of gold for fellow teammates. However, this can work against you if the enemy team reaches your camps first.
To stack a camp, you can either attack a unit in the camp or simply walk close to it. The neutral creeps will then attempt to chase you for a few seconds before returning to their initial position. Most camps can be stacked at around the 53-54 second mark. However, this timing varies depending on the spawn box size and the type of units involved. If done correctly, a new set of creeps will spawn at the minute mark.
The above method can be done multiple times, but timing might start to differ, as some creeps have auras which affect movement speed. Furthermore, all neutral camps can be stacked indefinitely, so long as all the creeps have escaped the camp boundaries.
Certain heroes can stack creeps very quickly, such as Tinker, Clockwerk, and Kunkka. With careful positioning and timing, Tinker can stack multiple camps at once using March of the Machines. Rocket Flare can block a camp or stack it from anywhere if Clockwerk damages the creeps. Torrent can temporarily eject units beyond the vertical boundaries of their spawn box if you use it just prior to the minute mark.
By using ranged abilities, some heroes can attack and stack creeps at little to no risk. For example, Alchemist, Medusa, Bristleback, and Beastmaster can attack ancient camps at a distance using Acid Spray, Split Shot, Quill Spray or Wild Axes. With some trees cleared, the Radiant ancient camp can be attacked from the ridge near the secret shop. The Dire side is even easier due to high ground and the creeps can be reached quite easily from the upper ridge.
See also: Creep Pulling
Although quite difficult to pull off, lane creeps can be used to absorb most of the damage dealt by a neutral camp. To do this, pull a neutral camp toward incoming lane creeps such that the incoming wave gets drawn toward the jungle. With careful timing, the camp will stack and the lane creeps can even be pulled toward harder camps which normally wouldn't interact with the incoming wave. If done incorrectly, any remaining creeps will venture back into the lane and eventually push out the creep equilibrium.
- The Ghost reduces your movement speed by 20%, making the easy camp more difficult to stack if it's present.
- The medium camp closest to the top T2 dire tower can be pulled; to do so it has to be done around the -:56 mark so the creeps are on the way down the steps and don't have vision of their camp