Monster Skills are skills or spells used by monsters. These are also known as monster traits and may be a passive ability or statistical difference rather than an active skill. They are also called monster affixes because of their similarity to item affixes, where keywords denote additional powers.
Diablo II[]
Monster skills may include combat spells and skills, but also self-affecting buffs or monster spawning abilities such as Lay Egg.
Some monster skills are modified versions of character skills such as Firebolt. However, some monsters (most notably Act Bosses) have unique abilities that are not available to players.
Diablo Immortal[]
Monster skills feature in Diablo Immortal, and are largely based on the ones seen in Diablo III (see below).
Diablo III[]
Diablo III introduces many new monster traits. Traits were called "affixes" particularly often among Diablo III discussions. Normal monsters do not have traits. A pack of Champion monsters each have the traits, which sometimes directly tie to each other. Rare or Unique monsters have traits as well, some of which are shared with their minions. Bosses, Rift Guardians, and some Unique monsters often have special, unique, or empowered versions of the typical traits, sometimes with a different graphical effect.
Diablo IV[]
Monster traits return in Diablo IV.
Damaging Skills
Fire — Embers • Eruption • Fire Arrow • Fireball • Fire Bolt • Fire Hit • Firestorm • Fire Wall • Flame Circle • Grenade • Hydra • Incinerate • Incineration Nova • Inferno • Meteor
Ice — Arctic Blast • Blizzard • Cold Touch • Fire Hit (Cold) • Freezing Charge • Glacial Spike • Hoarfrost
Poison — Poison Bolt • Poison Breath • Poison Cloud • Poison Spit • Poison Spray • Poison Sting • Poison Strike
Lightning — Lightning • Lightning Arrow • Lightning Globe • Red Lightning Hose • Shocking Hit • Spark Defense
Physical — Bite • Blow Dart • Charge (Berserk Charge) • Corpse Cannon • Destructive Strike • Divebomb • Ground Spikes • Ground Tentacle • Leap • Javelin • Leech-life Ball • Pummel •Quake • Quill Dart • Shockwave • Slam • Snatch • Spine Dart • Strike • Swipe • Sweep • Whirlwind
Magic — Beam • Blade Beam • Bomb • Bone Spirit • Hellish Projectile • Mana Bolt • Nova • Tornado • Torrent • Unholy Bolt
Non-damaging Skills
Indirect Attack — Blood Mana • Curses • Mana Rift • Minion Frenzy • Putrify • Spin Web • Stun • Vortex
Spawning — Bone Prison • Clone • Festering Appendages • Lay Egg • Mines • Revive • Summon Minion • Totem
Self-effect — Bone Armor • Burrow • Fly • Frenzy • Heal • Teleport • Vile Effigy