Hits against any target can potentially cause a Stun on that target, depending on the damage dealt. Stunning a target interrupts their current action and prevents them from taking actions for a short time. There are two types of Stun:

Light Stuns last a fraction of a second but can be inflicted frequently. Any Hit has a chance to cause a Light Stun. The chance is based on the damage dealt, up to 100% base chance for Hits that deal 100% of the target's maximum Life. Chances lower than 15% are treated as 0%.

Heavy Stuns occur when a target's Stun bar is filled and last multiple seconds. Hits cause Heavy Stun buildup based on the damage dealt. Players and their Minions usually cannot be Heavily Stunned, but players can receive Heavy Stun buildup where specifically mentioned while taking specific actions (such as raising their Shield, Parrying with a Buckler, or riding a mount).

Player Physical damage and Melee Damage each have 50% more Light Stun chance and Heavy Stun buildup. These bonuses are multiplicative with each other.
Monster Physical damage and Melee Damage have 100% more and 33% more Light Stun chance and Heavy Stun buildup respectively. These bonuses are multiplicative with each other.

Heavy Stuns occur when a target's Stun bar is filled, interrupts the target's current action and prevent them from taking actions for a few seconds. Hits cause Heavy Stun buildup based on the damage dealt. Players and their Minions usually cannot be Heavily Stunned, but players can receive Heavy Stun buildup where specifically mentioned while taking specific actions (such as raising their Shield, Parrying with a Buckler, or riding a mount).

While an enemy is Heavy Stunned, they cannot act and count as Immobilised. It will also be harder to Heavy Stun them again for a short time afterwards.

Physical damage, and player (but not monster) Melee Damage, each cause 50% more Heavy Stun buildup. For players, these bonuses are multiplicative with each other.

Players and their Minions usually cannot be Heavily Stunned, but players can receive Heavy Stun buildup where specifically mentioned while taking specific actions (such as raising their Shield, Parrying with a Buckler, or riding a mount). A player's stun bar only empties when they are not taking these actions or Heavily Stunned. While Heavily Stunned players cannot Block, Deflect or Evade.

Totems are allied constructs which use skills for you. Totems are not Minions and their skills benefit from your stats, though they have their own defensive stats and can be damaged or killed.

Totem Limit is shared between different types of Totem by default.

Your allies include other players, Minions, and any other entity that fights alongside you and has its own stats.

You do not count as your own Ally.

Remote Skills are Skills that are performed for you by a different entity, such as a Totem, Trap, or Clone. Minions are not Remote Skills.

Reviving Minions heal after avoiding damage for a short time, and automatically revive after a short delay when killed. This delay is reset whenever another Reviving Minion dies.

Sacrificing is loss of a resource (commonly Life, Mana or Energy Shield) that does not count as taking damage. You cannot Sacrifice a resource you do not have. Sacrificing Life cannot reduce you below 1 Life, but Sacrifices you cause on others (such as Sacrificing Minion Life) can lead to their death.

Minions whose durations expire or that are despawned by the player are considered to have died. However, effects that state they trigger when a Minion is Killed do not trigger in these cases. Minions are only Killed if they reach 0 life, though this can be caused by their summoner as well as enemies.

Some Minions can be Commanded to perform certain actions. This requires you to use the corresponding Command skill, which will cause one of your Minions to carry out the Command.

Offering Skills target an active Skeleton Minion to create an Offering Spike. Offering Spikes grant various Buffs to you or your Minions, and can even directly damage Enemies. Offering Skills are themselves damageable Minions and their Buffs are lost if they die.

Companions are a type of Reviving Minion that are more complex and powerful than typical Minions. By default you can only have one Companion of any type summoned at a time.

50% of damage taken from Monster is taken from Monster's Pack Minions instead

50% of damage taken from Monster is taken from Monster's Pack Minions instead

Monster periodically revives Pack Minions.

Monster periodically revives Pack Minions.

Monster's Pack Minions have 25% increased Damage and 50% increased Life.

A Pack Monster or Minion is a Monster that naturally spawns as a part of a Monster Pack in areas or from mechanics like Strongboxes.
Monsters or Minions created by other Monsters do not count as Pack Monsters or Minions.

A Temporary Minion is a Minion that has a Duration, which dies after it's Duration has passed.

Minion Reforming is similar to Minion Reviving, but only occurs at the end of the "Minion Reforming" Buff Timer that is granted while Persistent Minions are dead, as opposed to other effects that may revive Minions.

Gigantic Minions have 20% more Maximum Life, 20% more Damage and 20% increased size.

Umbral Souls grant varying Buffs depending on the kind of Skeletal Minion being replaced, as follows -

Umbral Souls from:
• Skeletal Warriors grant 15% increased Attack Damage.
• Skeletal Snipers grant 15% increased Projectile Speed.
• Skeletal Clerics grant 30% increased Energy Shield Recharge Rate.
• Skeletal Arsonists grant 15% increased Area of Effect.
• Skeletal Storm Mages grant 25% increased Spell Damage.
• Skeletal Frost Mages grant 35% increased maximum Energy Shield.
• Skeletal Brutes grant 60% increased Stun buildup.
• Skeletal Reavers grant 6% increased Skill Speed.