Creep stacking is the act in which pulling creeps at any spawn point from the 51s - 57s mark creates a second set of creeps at the same location. This can be effective for splash damage heroes on the Ancient creeps later on in the game for farming.
Stack Limit
You cannot stack more than three sets of creeps at the same spawn point. When you have three sets of creeps stacked, don't hesitate to kill them all to get your gold reward.
Double Stacking Two Different Spawn Points
Double or nothing!
This is a complicated version of Double Stacking, as it must be timed perfectly. The goal of doing this is to create a double spawn at two different neutral camps.
This can be done on the Hellbourne side using the neutral spawn closest to the top rune and also the weak neutral spawn. To do this you must attack the neutral camp closest to the rune at 51s - 52s, and then run directly up the hill towards the weak neutral spawn, when up there attack one of the creeps and then move directly left. This should create two sets of creeps in both spawn points. This is a much more advanced move and can only be done with a ranged hero.
On the Legion side it is a bit easier to time but requires a Rune of Blight or a Logger's Hatchet because you must eat a tree to pull it off (see the picture below).
This will be using the two eastern most neutral spawn. Before trying this you must eat a tree that opens a path way through the southern most camp.
Then precede to attack the northern camp at 51s - 52s and then run down through the created pathway and gain aggro of this wave as well. Then pull the creeps to either the left or right side and this should create two sets of creeps at two different spawns.
