Hit
The term hit refers to a strike dealt by an attacker to a target, which usually causes damage. The damage can be mitigated up to 0, but can never be negative. Damage dealt by hits always has one of 3 damage sources: attack, spell or secondary. On the contrary, damage over time never hits.[1]
Besides the amount of damage, its types and source, hits also contain/transfer information about other related mechanics and effects, such as:
- critical strikes
- penetration and resistance ignoring (e.g. Inevitable Judgement)
- accuracy (for attacks only)
- modifications to target's block and dodge chances (e.g. Module Error: No skills found with q_where = skill.active_skill_name="Block Chance Reduction Support")
and others.
On/when hit effects
There are countless number of effects that can occur after hit is completed and damage is dealt:
- gain temporary buffs (e.g. charges)
- inflict debuffs (e.g. status ailments, curses or bleed)
- stun
- knockback
- gain life, mana or energy shield
- culling strike
- skill-specific effects (e.g. Module Error: No skills found with q_where = skill.active_skill_name="Arctic Breath"'s explosion).
Additionaly some effects have specific requirements, such as Module Error: No skills found with q_where = skill.active_skill_name="Life Gain on Hit" only working with attacks, culling strike only affects enemies with less than 10% life, and 
Voll's ProtectorVoll's Protector
Holy ChainmailArmour: (388-582)
Energy Shield: (82-122)
Movement Speed: -5%Requires Level 35, 53 Str, 53 Int(100-150)% increased Armour and Energy Shield
50% reduced maximum Mana
Gain a Power Charge for each Enemy you hit with a Critical Strike
Inner ConvictionAlthough a great leader during the war,
Voll proved disastrous in times of peace.
's effect needing a critical strike.
Conditional modifiers
There are modifiers that can apply their effects only when a certain condition is met. If such modifier requires a check for target's condition, it only works with hits because a condition can change.[2]
For example, more Damage against Chilled Enemies from Module Error: No skills found with q_where = skill.active_skill_name="Hypothermia Support".
References
- ↑ Mark_GGG (February 21, 2016). "GGG, can we get some answers on Conversion please?". Official Path of Exile Forums. Retrieved February 21, 2016.
- ↑ Mark_GGG (June 9, 2016). "Mechanical Questions Thread". Official Path of Exile Forums. Retrieved July 05, 2016.