What is Stack?

Stack - an additional group of neutral creeps created by taking away creatures at a certain time. If done correctly, a new wave will appear in place of the old creeps and several stacks will appear in the camp at once, which will allow you to farm more gold and experience at once. You can also stacking creeps with abilities. For example, Kunkka's Torrent throws units into the air, temporarily removing them from the spot. If you do this at the right moment, a new group of creeps will appear in the camp, so the stack will happen even without direct removal.

Alternatively, “stack” can refer to the number of charges an ability or effect has accumulated. Examples:

• Positive: Bristleback accumulates Warpath stacks, which grant bonus damage to basic attacks.
• Negative: Shadow Fiend's Shadowraze debuff stacks deal increasing damage and slow the target as they accumulate.