Creep

Overview

In DotA, creeps spawn every 30 seconds in each of the three lanes, although the start time depends on which of the Primary game modes is selected. These creeps get stronger as time passes by, with increases in damage, hit points, and numbers, and receive significant upgrades in the first two aspects when the enemy's Barracks in the corresponding lane are destroyed. Once all six Barracks are destroyed, the opposing team's creeps become Mega Creeps, which generally spell the end of the game with their incredibly high damage and hit points.

Creeps add a roleplaying element to gameplay, providing experience points and gold when killed by your faction (Sentinel/Scourge), your ally or yourself. Experience points are given out in a 1000 AOE around the dying creep, and gold is given only to the killer, making the ability to Last Hit crucial in Farming gold. In any given game, Sentinel/Scourge creeps will be the primary source of gold and experience for most of the players, although other methods that center on killing Neutral Creeps or enemy Heroes are common as well.

Artificial Intelligence

The hardcoded AI of all units (non-neutral) is if the unit is idle (not executing an order), it will attack the closest enemy in its acquisition range (which is not the same as vision range) and continue to attack/persuade until the enemy dies, the unit dies or it gets out of the acquisition range for some time. Besides that, there's hardcoded "Call for Help Range" (600), which makes an idle unit attack the enemy if an ally in the range is attacked. This by itself wouldn't make harrasing the opponent more difficult, because allied creeps are occupied fighting the enemy creeps. This is where triggers come in.

This is important on the early stage of the game because when a hero tries to harrass an enemy with physical attacks, he may get more damaged via the creeps, than the damage he inflicted to his opponent. Spells are not considered attacks, and will not generate aggro on the hero (Arrow auto-cast skills like Bone Fletcher's Searing Arrows are considered spells too when casted manually, not left on auto-cast).

Notes

• creep aggro lasts for 2 seconds
• the attacker gets aggro from all enemy creeps in 500 AoE from him, so you can order an attack command across the map (to a different line for example) and still get aggroed
• you get aggro even if you don't click on the enemy, but attack him by autoattack or attack ground command (this is where trigger "OnAttacked" comes in)
• trigger "OnAttacked" applies to enemy creeps and neutrals as well (can help with creep pulling).

Miscellaneous

• Super Creeps are also classified as creeps. However, they require an activation mode (-SC) to appear.