2345 is a 5v5 arena composition consisting of the following classes and talent specializations:

This composition came to rise during Seasons 1 and 2, and remains extremely popular.[citation needed] It depends heavily on the Mage's "[Shatter] Combo" (a [Frost Nova] followed by a [Frostbolt] and [Ice Lance]), and the Shaman's burst ability. The name is based on the joke that the Shaman must only hit 4 buttons -- 2,3,4, and 5-- to kill an opposing player. The corresponding abilities are [Heroism], a [Lightning Bolt], a [Nature's Swiftness] instant [Chain Lightning], and a [Frost Shock]. This composition's weakness largely lies in the lack of crowd control abilities (only the Mage has a silence and a spammable crowd control) and lasting power, primarily due to a Mage's more limited mana pool and inability to drain or regenerate mana as quickly.

A popular variant of this composition called 2346 is run with a [Siphon Life]/[Soul Link] or Felguard Warlock instead of a Mage.

Later of in Wrath of the Lich King the composition of 2346 was run with a Destruction Warlock instead of a Mage.