Hit

The term hit refers to an effect that applies a discrete amount of damage to a target instantaneously. The damage can be mitigated down to 0, but can never be negative. Damage dealt by hits always has one of 3 damage sources (attack, spell or secondary, but note that damage over time never hits.) and is combined of any 5 damage types (physical, fire, cold, lightning or chaos).

Besides the amount of damage, its type and source, 'hit packages' also contain certain mechanics and effects, such as:

• critical strikes
• ailments
• penetration and resistance ignoring (i.e. Inevitable Judgement)
• accuracy (for attacks only)
• modifications to target's block and dodge chances (i.e. Block Chance Reduction SupportBlock Chance Reduction SupportSupport, Duration
  Icon: B
  Level: (1-20)Requires Level 18Supports any skill that hits enemies.Per 1% Quality:1Superior2AnomalousSupported Skills have 0.25% reduced Enemy Block ChanceSupported Skills have 2% increased Overpowered EffectEnemies have -(10-20)% chance to Block Attack or Spell Damage from Supported Skills
  Enemies have -(20-29)% chance to Dodge Attack or Spell Hits from Supported Skills
  Supported Skills inflict Overpowered for 4 seconds when Blocked
  Overpowered applies -5% chance to Block Attack and Spell DamageThis is a Support Gem. It does not grant a bonus to your character, but to skills in sockets connected to it. Place into an item socket connected to a socket containing the Active Skill Gem you wish to augment. Right click to remove from a socket.)

and others.

On/when hit effects

"On Hit" effects are when the player hits the enemy, and "When Hit" is when the enemy hits the player. In general, most effects are applied after the hit is completed and damage is dealt, since magnitude of damage is used to compute the magnitude of effect. These include, but are not limited to:

• gain temporary buffs (e.g. charges)
• inflict debuffs (e.g. curses or bleed)
• stun
• knockback
• gain life, mana or energy shield
• culling strike
• skill-specific effects (e.g. Creeping FrostCreeping FrostSpell, Projectile, Duration, AoE, Cold
  Level: (1-20)
  Cost: (7-20) Mana
  Soul Gain Prevention: 0 sec
  Cast Time: 0.60 sec
  Critical Strike Chance: 6.00%
  Effectiveness of Added Damage: 80%
  Projectile Speed: 844
  Radius: 12Requires Level 12Fire an icy projectile that bursts on impact or when reaching the targeted area, dealing area damage and creating a chilling area that deals cold damage over time. This area will creep across the ground towards nearby enemies until its duration expires.Per 1% Quality:1Superior2Anomalous3Divergent4Phantasmal0.5% increased Area of Effect1% increased Skill Effect DurationFires an additional ProjectileChilling Area has 2% increased Movement SpeedBase duration is 5 seconds
  Deals (11-383) to (16-572) Cold Damage
  Can have up to 10 Chilling Areas
  Deals (16.7-1391.2) Base Cold Damage per second
  Modifiers to Spell Damage apply to this Skill's Damage Over Time effectPlace into an item socket of the right colour to gain this skill. Right click to remove from a socket.'s explosion).

Additionally, some effects have specific requirements, such as Life Gain on Hit SupportLife Gain on Hit SupportAttack, Support
Icon: h
Level: (1-20)
Cost & Reservation Multiplier: 140%Requires Level 8Supports attack skills.Per 1% Quality:1Superior2Anomalous3Divergent+0.5 Life gained for each Enemy hit by Attacks from Supported SkillsSupported Skills deal 2% increased Damage when on Full Life+0.1 Mana gained for each Enemy hit by Attacks from Supported Skills+(6-44) Life gained for each Enemy hit by Attacks from Supported SkillsThis is a Support Gem. It does not grant a bonus to your character, but to skills in sockets connected to it. Place into an item socket connected to a socket containing the Active Skill Gem you wish to augment. Right click to remove from a socket. only working with attacks, culling strike only affects enemies with less than 10% life, and 's effect needing a critical strike.

Conditional modifiers

There are modifiers that can only apply their effects when a certain condition is met. Modifiers that are conditional on properties of the target do not affect damage over time because only hits are able to check someone else properties. For example, more Damage against Chilled Enemies from Hypothermia SupportHypothermia SupportCold, Support
Icon: D
Level: (1-20)
Cost & Reservation Multiplier: 140%Requires Level 31Supports any skill that deals damage.Per 1% Quality:1Superior2Anomalous3DivergentSupported Skills have 1.5% increased Chill Duration on EnemiesSupported Skills have +1% chance to Freeze Enemies which are ChilledEnemies Frozen by Supported Skills have -0.2% to Cold ResistanceSupported Skills deal (20-29)% more Damage with Hits and Ailments against Chilled Enemies
Supported Skills have +20% chance to Freeze Enemies which are Chilled
Supported Skills deal (20-39)% more Cold Damage Over TimeThis is a Support Gem. It does not grant a bonus to your character, but to skills in sockets connected to it. Place into an item socket connected to a socket containing the Active Skill Gem you wish to augment. Right click to remove from a socket. doesn't increase damage from DoTs.

gloves will prevent your hits from killing enemies who are not frozen. This will not stop enemies from dying from your damage over time or minions.

Items that enable self-damaging

Items that hit:

• (on use)
• (on igniting an enemy)
• (on using a movement skill)
• (on minion death)
• (on skill use)

Items that do not hit, but still deal damage to you:

• (on kill)