Ultimate

Ultimate
A Hero's last skill, which can be trained at Level 6, Level 11, and Level 16, with the exception of Invoker's Invoke, which can be trained at levels 2, 7, 12, and 17. In general, Ultimates have long cooldowns due to their sheer impact and effect and often have the potential to be a game changer. Earthshaker's Echo Slam and Sand King's Epicenter are examples of such. Hero ultimates can be an active skill or a passive skill.

Among ultimate skills, there are some ultimates which don't have a particularly long cooldown such as Sniper's Assassinate, Pudge's Dismember, Invoker's Invoke, and Slardar's Amplify Damage. Some ultimates, while being active skills, don't even have a cooldown, such as Leshrac's Pulse Nova, Tinker's Rearm, Enchantress's Impetus, Storm Spirit's Ball Lightning, and Pugna's Life Drain improved by Aghanim's Scepter.

Some heroes also have passive skill ultimates which greatly enhances the hero's capability in their role, such as Riki's Permanent Invisibility, Drow Ranger's Marksmanship, and Tiny's Grow. Skeleton King's Reincarnation is a unique ultimate where it is a passive skill by nature but has a cooldown and mana requirement typical of an active skill. Other ultimates have passive and active abilities, like Slark's Shadow Dance. When he is not seen on the enemy minimap, he has massive health regeneration and movement speed. He can also activate his ult to go invisible for 5.5 seconds where attacking and casting spells wont make him visible again.

Ultimates, unlike normal abilities, are usually able to target a unit under a magic immunity effect, such as Black King Bar. They will rarely damage such a unit, but other effects such as slows or stun will generally apply. This makes ultimates, especially those with stun effects, incredibly powerful, since enemy Heroes cannot block the effects.

Aghanim's Scepter
Improve the ultimate of some heroes