Gear score

Gear score is a numerical value based on the statistics of a player's gear. It is (supposedly) the maximum potential of a player's performance. However, it is up to the player to perform that well. In addition to item level (ilvl), the item's actual statistics or abilities may or may not be included for calculation, as determined by specific formulas or addons.

Most commonly, gear scores are a metric used to evaluate the relative strength of a player's equipment as a way of determining if that player meets a given threshold to join in certain raids or groups going through an instance. It should be noted that a given gear score, no matter which formula is used, does not necessarily mean that other players cannot demand higher scores from others before joining a raid or group.

Despite the possible flaws in the system, gear score can be a useful tool in determining an individual player's readiness for certain content. Rather than risking the waste of time and money on wipes and repair bills, gear score can provide a basic indication that a player is likely to possess gear sufficient to run (or even trivialize) the content in question. There is no substitute for checking a player's choice of gems, enchants, glyphs, and spec, plus knowledge of appropriate caps (hit, haste, and/or crit), all of which reveal far more about a player than for what gear he or she has managed to win rolls or purchased by running heroics.

That said, when used as an initial assessment of a player, followed by inspections of their Armory profile (which does display things like item enhancements and achievements), gear score can allow the quick and efficient assembling of groups and raids intending to take on difficult content. Be warned: reliance on gear score, without following up the initial assessment with the armory or inspecting, is in fact counterproductive. It degrades the community by encouraging less knowledgeable players to "upgrade" based strictly on item levels, as well as decreasing the motivation of some players to improve (as they receive raid invites and rolls on loot without needing to do so).

Controversy
The usage of gear scores has caused a large amount of controversy due to a proportion of players who view it as unnecessary and distracting in the face of others options like DPS or Achievements.

Teammate screening
The largest source of complaints appears to arise from the fact that while gear score addons/websites may calculate and suggest a gear score for certain content, frequently players have arbitrarily raised the minimum score needed before they will allow others to join them. Motivations for this may include a desire by some players to either decrease the chance of failure in the instance, or to increase the ease or speed of gameplay. Often, players will seek to run older content as fast as possible as a means to farm emblems as quick as possible. These groups frequently reject new players who may actually need gear from such content.

Players often feel they are skilled enough to overcome their lack of gear. They feel upset that they are not given the chance to prove themselves because they fail whatever gear score requirement was imposed by the raid leader. A veteran player with a low gear score can outperform a newer player with a high gear score. Similarly a high gear score tank can be the counterweight for a low gear score healer or vice versa.

Wrong-class gear
Until Patch 4.0.1, the GearScore add-on (now called PlayerScore) did not penalize gear whose stats were inappropriate to a player's class or role or were only useful in PvP, nor did it consider weapon or armor type.

Caps
Even if a player's gear is class- and spec-appropriate, gear score add-ons do not take soft or hard caps into account. Reforging greatly reduces the impact of this problem, but only if the player is aware of the relative value of different secondary stats to him or her.

Decline and alternatives
In Cataclysm, two assessment methods have caused gear score to fall into disuse.

Item level
The game now provides average equipped item level, which is adequate if only a sanity check is needed of the player's assessment that he or she is geared.

Rawr and Simulationcraft
The tools Rawr and Simulationcraft provide detailed estimates of a player's potential damage per second, healing per second, or chance to survive and hold aggro as a tank; these are the best way to objectively score a raider's gear. Since they use thousands of iterations and can standardize both boss mechanics and raid buffs, they are far more precise than estimates based on damage meters or combat-log parses.