Combat Results

When you attack something with an attack or spell in WoW, there are several possible results.  Most of these results are relatively clearly communicated to the player, but not all of them.  Before discussing the combat table itself in a later post, first I want to enumerate and describe the different results that appear on the table, as well as other results that can occur when you attack a target.  Future posts will discuss how to increase or decrease the chances of each of these types of result.

1. Hit:  The "default" or "normal" result of an attack is a hit.  The results of the hit depend on the attack or spell; a normal melee attack does weapon damage, reduced by armor and other damage reduction.
2. Critical:  A critical hit with a melee attack normally does twice the damage a hit would have done.  A critical hit with a spell does 1½ times normal damage by default, though many talents and class abilities modify this.
3. Miss:  An attack may also miss.  There are many ways for an attack to fail to result in damage, of which the miss result is only one.  Misses are to be distinguished, for example, from the following two types of result.
4. Dodge:  The target may dodge the attack, resulting in no effect.  This is a different type of result than a miss, and is reported differently.  Only melee attacks can be dodged (what exactly counts as a melee attack as opposed to a ranged attack or spell is not always obvious, however).
5. Parry:  The target may parry the attack, resulting in no damage.  Blizzard has announced plans to change this result in Cataclysm; in that expansion, a parry will result in 50% damage reduction for the parried attack and the next attack (it's not clear at this time if "next attack" means the next attack on the parrying target from any source or just the next attack on the parrying target from the same source as the attack that was parried). * Only melee weapon attacks can generally be parried, but see below.
6. Deflect:  Occasionally, but rarely, you may see a "deflect" result reported in your combat log.  A deflect is the same as a parry, but is for some reason reported differently.  You will never see this result for an auto-attack, but only for spells and abilities (a paladin's Hammer of the Righteous attack, for example, can be deflected, by not parried).  Most spells cannot be deflected, except by a hunter under the effect of Deterrence.
7. Block:  The target may block the attack, resulting in partial damage.  Presently, the amount of damage reduction from a block is a static number depending on the target's Block Value statistic, which is increased directly by gear and talents and indirectly by Strength.  This can result in no damage done if the target's Block Value is greater than the damage done by the attack (after applying armor and other damage reduction).  Such full blocks are treated as fully avoided attacks.  In Cataclysm, full blocks will no longer be possible.  Blizzard is planning to remove the Block Value statistic entirely and make all block results reduce damage from the attack by a percentage.
8. Resist:  Like blocks, resists can be full or partial.  Weapon attacks generally cannot be resisted; this type of result applies only to spells.  A full resist registers in the combat log as a "resist," while a partial resist will specify what portion of the damage was mitigated by resistance.  Exactly how much damage is resisted depends on factors such as the level of the target relative to that of the attacker and whether or not the target has any resistance (Fire Resistance, Arcane Resistance, etc.) to the relevant spell school; there is always also a random component.  Some spells, particularly those that do not deal damage, cannot be partially resisted.  If they are resisted at all, they are fully resisted for no effect.
9. Absorb:  If the target of an attack is under the effect of a damage shield spell like a priest's Power Word: Shield or an ice mage's Ice Barrier, the attack may be absorbed.  Damage shields typically absorb a fixed amount of damage, and every point of potential damage subtracts from that amount.  An attack's result will be reported as fully absorbed if the remaining potential of the shield is greater than the amount of damage the attack would do.  Unlike a full block or full resist, a fully absorbed attack may still apply a secondary effect.  For example, if the damage from a mage's Frostbolt is absorbed by a damage shield, the target may still be affected by the slowing effect of the spell.  Partial absorption is also possible when the amount of damage done by the attack is greater than the remaining damage absorption potential of the damage shields on the target.
10. Glancing Blow:  This result is only possible when the target of the attack is a non-player character of a higher level than the attacker.**  A glancing blow does reduced damage based on the difference between the attacker's Weapon Skill and the target's Defense Skill, which is a function of the target's level (all non-player characters of the same level have the same Defense Skill).  The case we mostly care about is a player with maximum Weapon Skill attacking a Boss level target; in that case, the damage reduction is 30%.
11. Crushing Bow:  This result is the counterpart of the Glancing Blow when a higher-level target is attacking a lower-level target.  In the current state of the game, it is not possible for a maximum-level player to receive a Crushing Blow, and only non-player characters may deliver Crushing Blows, so the only time you will ever see this result is when you are leveling and attempting to fight a mob at least four levels higher than you.
12. Immune:  Targets are sometimes immune to the damage and effects of spells and attacks.  For example, a paladin under the effect of Divine Shield is immune to all damage and the effects of all player spells (with the sole exception of a priest's Mass Dispel) and most non-player spells, though there are several non-player spells in the game that ignore player immunities.  Sometimes a target may suffer damage from a spell even when you get an "immune" result for that same spell; in such cases, it is the secondary effect of the spell that the target is immune to.  For example, many bosses are immune to the slowing effects of spells like Frostbolt, but may still take damage from them.
13. Evade:  This result occurs only when the target of an attack is a non-player character.  Any target that evades one attack will evade any attack until whatever condition is causing it to evade is removed; such a target is said to be "evading" and is essentially immune to all attacks and effects and regenerates health as though it had exited combat.  This state is triggered when a mob is pulled far enough away from its spawn location that it drops aggro and quickly speeds back to where it came from, when it is trapped by or stuck in the terrain of the game world, or when it is impossible for it to reach its attacker with any attacks.  Essentially, this result indicates that something has gone wrong, and the mob needs to "reset" itself; it's a kind of error state rather than a true combat result.

Those are all the possible results of an attack in World of Warcraft.  Not all of them can occur for every type of attack or every combination of attacker and target.  The chances for several of these results can be influenced by the attacker's or the target's stats; several others can be altered by situational factors like the way the attacker and the target are facing.  The real interest in distinguishing all these attack types is so that we can be clear about how to influence the chance for each result, so that we can increase the chance of good results and decrease the chance for bad results, as I will spell out in detail in future posts.

*Blizzard has officially decided against changing parry; it is now a 100% damage reduction against the parried attack, just like a dodge or miss.
**This is not strictly true; a glancing blow can occur against a target of the same level if the attacker's Weapon Skill is not at its maximum possible value.  I neglect this complication in part because Weapon Skill is going away in Cataclysm.