- Cap can also refer to Capture, as in Capture the Flag.
Cap, soft cap, or hard cap can refer to several different things depending on the context.
"Cap" refer to the level cap, or the highest level that can be currently obtained. During the release of World of Warcraft, the level cap was 60. The level cap has been raised for each successive expansion. In The Burning Crusade it was increased to 70, and in Wrath of the Lich King it was further increased to 80.
Finally, "cap" or sometimes "soft cap" may be used when referring to gear itemization. For example, players theorycraft about the hit cap, the expertise cap, the dodge cap, the spell penetration cap, and others.
A "hard cap" is a point beyond which a stat becomes useless. For example, 1400 armor penetration rating bypasses 100% of all armor, so more rating has no effect. A spellcaster with 17% increased chance to hit will never miss a boss, so this is the hard cap for hit rating for casters.
A "soft cap" is either the point at which a stat stops providing a particular benefit but continues to provide others, or the point beyond which a temporarily active buff will push the stat over a hard cap. For an example of the first, a defense rating of 689 is sufficient to eliminate the chance of a boss getting a critical hit against you, so further defense will not have any effect on your chance to be critically hit, but will still increase your chance to parry, dodge, block and be missed by attacks. For an example of the second, a character with a will occasionally get 678 bonus armor penetration rating. If the character has 732 base rating, this will be sufficient to temporarily reach the hard cap of 1400 noted above. Further base rating will cause some of the Scorpion's bonus to be wasted. However, the additional rating will still provide a benefit when the Scorpion's proc is not active.
Soft and Hard Caps at Level 80
The following is an overview of some of the rating caps at level 80. It should be noted that caps are often augmented by extraneous factors, such as buffs, talents, or racial abilities. One should therefore consult the main articles for an overview on what the cap may be in any given raid or PvP situation.
- Main article: Armor penetration
The armor penetration hard cap against a raid boss is 1400, which will remove 99.99% armor.
- Main article: Melee mitigation#Block cap
Block cap refers to when a warrior or paladin tank has enough combined miss, dodge, parry, and block chance to push regular hits off the attack table, meaning that all suffered attacks will either be missed, dodged, parried, or blocked. In The Burning Crusade, this was a vital mechanic for tanks in order to remove crushing blows. In Wrath of the Lich King, raid bosses no longer perform crushing blows, but removing regular hits entirely may still be sought after by tanks. The block cap is against a raid boss is 102.4%, meaning a tank must have a combined 102.4% chance to dodge, parry, block or be missed to push regular hits off the attack table.
- Main article: Critical strike#Crit Cap
The crit cap against a raid boss depends on the amount of hit and expertise rating a player has, because higher hit and expertise lessens the chance of an attack missing, or being parried or dodged, thus opening up more room for the attack being a critical strike. Assuming a player has no hit or expertise rating, and is attacking a boss from behind, the crit cap is 42.5% for dual-wield attacks and 61.5% for single-wield attacks. As a player obtains more hit and expertise rating, the cap number increases, but it may never exceed 71%, as there will always be a 24% chance of a glancing blow, and a 5% chance of a crit supression.  Special attacks may not produce glancing blows, and will as such have an even higher crit cap.
- Main article: Defense
The soft defense cap for being uncritable against a raid boss is 540 defense skill, which requires 689 defense rating for a warrior or paladin which is at 400 defense skill with no gear bonuses. Death Knights may attach runes to their weapons which give them defense skill, lowering the required number of defense rating for a Death Knight to reach the soft cap. Uncritability may also be achieved through 5.6% resilience, which requries a resilience rating of 460. Additionally, resilience and defense may be combined to achieve uncritability. Note that defense rating, unlike many other ratings, does not become useless once the cap has been reached, as defense rating will always increase the chance of a block, parry, dodge, or miss.
- Main article: Expertise#Expertise caps
The soft expertise cap against a raid boss is 26, which is obtained through 214 expertise rating. For heroics and other 5-man instance, this number is lower. The cap number may also be augmented by talents, glyphs (for paladins), and/or orcish, dwarven, or human racial bonuses. For melee dps, the soft cap should be enough, assuming they are attacking the raid boss from behind. Generally only tanks need to worry about the hard cap, which will make them unparriable. The hard expertise cap against a raid boss is 56, which is obtained through 460 expertise rating.
- Main article: Hit#Hit rating cap
The hard hit cap against a raid boss for all single-wield attacks, ranged attacks, and special dual-wield attacks is 263. The hard hit cap for a dual-wield auto-attack is 886. For heroics and other 5-man instances, this number is lower. The cap number may also be augmented by talents and/or the presence of a Draenei in the raid.
- Main article: Resilience#Resilience cap
The current resilience soft cap in PvP is 1415, which will reduce damage from a critical strike by 33%. Exceeding this number is not wasted, however, as higher resilience will reduce the chance of being critically hit.
- Main article: Spell hit#Hit rating caps for level 80
The hard hit cap against a raid boss for all spells is 446. For heroics and other 5-man instances, this number is lower. The cap number may also be augented by talents, debuffs on the target, and/or the presence of a Draenei in the raid.