Cross-realm zones (colloquially known as CRZ) is a feature in which certain zones in the game are populated with players from multiple realms. This feature is only intended for zones that usually have a low population of players in them.
Currently only realms around the same time zone (within 3 hours of each other) will be merged together.
Zones not affected
Certain zones will not be affected by the feature, including:
Notes
- Only realms of the same type will be matched together, so a PvP realm will not merge with a PvE or RP realm, however, RP realms can merge with RP-PvP and RP-PvE realms.
- This feature is not intended to affect the fishing tournaments' winners, though you will still have to compete cross-realm for fishing pools.
- Low populated zones include most of the factions' major cities and are currently part of the system, even though it was stated they would not be.
- Flying between zones will cause riders, on passenger mounts, appear to dismount after entering the new zone but are quickly thrown back onto the mount. Before this was fixed, riders would be dismounted and begin parachuting down to the ground.
Known issues
- When leaving a major city into a cross-realmed zone (such as Stormwind to Elwynn) in a passenger mount such as the
[Reins of the Traveler's Tundra Mammoth] with a player passenger on board, the player passenger will be dismounted (suddenly placed on the ground, standing) and the NPCs returned to their positions on board.
Cross-Realm Groups
With the exception of zones that are never cross-realm (notably Stormwind and Orgrimmar but only on RP realms), generally all members of a cross-realm group will be phased to occupy the same copy of a zone. The rules governing which copy of the zone the group sees are complicated. Roughly the selection operates as explained below.
- In the following rules, home zone refers to the copy of the zone that a character would see while ungrouped.
- Generally all characters on one realm or group of connected realms share a home zone.
- Due to cross-realm zones some characters from different (unconnected) realms will also share a home zone.
- A newly-created group (ie with a single member) starts by using the leader's home zone.
- From this point forward, group leadership no longer affects phasing.
- Phasing to a different copy of a zone may only be triggered by a change in group membership (a member joining or leaving).
- If one group member exceeds the level of anyone else in group, the group will phase to his home zone.
- If two or more group members with different home zones are tied for maximum level, the copy housing the most max-level characters is used.
- In the case of a tie in the previous rule, the zone copy housing the most characters of any level (but ignoring level 1 toons) is used for the group.
- If there is still a tie, no phasing occurs and the group remains on the most recently-selected copy of the zone.
- The Online/Offline status of group members does not affect phasing decisions.
Patches and hotfixes
Patch 7.0.3 (2016-07-19): Cross-realm zones have been enabled for the continent of Draenor. 
Patch 6.0.2 (2014-10-14): Cross-realm zones have been enabled for the continent of Pandaria. 
Hotfix (2012-09-20): Cross-realm zones no longer bring together players who are more than 3 timezones apart. - Patch 5.0.4 (2012-08-28): Added.
