Justice Points

Justice Points were rewarded for completion of high level PvE dungeons and raids and used as currency for gear and other rewards that were oriented toward the PvE style of play. Points were commonly rewarded after killing a boss or after completing a dungeon that was initiated using the Dungeon Finder. One requirement is that all participants of the dungeon must conform to level requirements, or else no reward will be given to any participant.

Justice Points replaced Emblem of Frost and Emblem of Triumph. Mists of Pandaria based raid content also rewards Valor Points. The cap for Justice Points is 4000. After each patch, Justice Points above the cap are converted to per Justice Point.

Justice Points and Valor Points were removed in Patch 6.0.2 and per point was mailed to each player to replace them. Items previously purchased using Justice or Valor now cost gold, with the exception of Heirlooms and Justice-purchased rep tokens, which have been removed.

Wrath of the Lich King gear (ilevel 200-264)
Before Patch 4.0.1, Wrath of the Lich King gear used the five-tier Emblem system for dungeon and raid rewards. The emblem costs have since been converted to Justice Points.

Burning Crusade gear (ilevel 110-146)
Before Patch 4.0.1, The Burning Crusade gear used Badge of Justice system for dungeon and raid rewards. The emblem costs have since been converted to Justice Points.

Conversion of Emblems to Justice Points
When players first logged in after Patch 4.0.1, the number of Justice Points they have will be calculated as follows:


 * JP = 11.58 * (EoT + EoF)

where:
 * JP = the number of Justice Points;
 * EoT = the number of Emblems of Triumph;
 * EoF = the number of Emblems of Frost.

However, if the one-time emblem-to-point conversion granted the player more than 4,000 Justice Points, they were unable to accumulate any additional Justice Points until they had spent the excess. In Patch 4.0.3a, any Justice Points above 4,000 were immediately converted to gold at a ratio of per Justice Point.

Other emblems, badges and tokens
,, and were immediately converted to gold (and not Justice Points) at a ratio of  per emblem in Patch 4.0.1. were also immediately converted to gold at a rate of per badge.

PvP-based currency was converted to Honor Points much the same way.

Other, specific currencies such as Champion's Seals was not converted.

Comparison of purchasing power
With the introduction of Justice Points (Patch 4.0.1), that replaced Emblem of Frost and Emblem of Triumph, players will be able to use the same currency to purchase both Tier 9 and Tier 10, potentially skipping the earlier in favor of the latter. Obtaining Tier 10 is now in comparison faster and easier.

The conversion did affect the prices of Heirlooms as well, from using Emblem of Heroism to using the same currency. The prices for Heirlooms seems to be equated for the Justice Point income at level 85, which at level 80 means relatively higher costs. Example:
 * Prior cost was 65 Emblem of Heroism. Being that the average Random Heroic gave about 6 Emblems, you needed 10-12 runs to earn this.
 * Patch 4.0.1 changed the cost to 3500 Justice Points. As a Random Heroic at level 80 gives 55, 71, 87 or 103 points, you would need 35-45 runs to earn this.
 * Patch 4.0.1 changed the cost to 3500 Justice Points. As a Random Heroic at level 80 gives 55, 71, 87 or 103 points, you would need 35-45 runs to earn this.

Trivia

 * The name of this particular point system was obviously inspired by the iconic Badge of Justice currency system originally appearing in The Burning Crusade expansion.