PVP Only: Global damage / healing reduction by 5% (6.6% for healing) every 10 levels, up to a maximum of 30% (40% for healing) reduction at level 60 and beyond. (Not applied under WOTLK expansion)
Additional class balance/tweaks for expansions prior to WOTLK, you can find the details here
All raids scaled to 10man with proper balance.
Instant mail delivery.
All Flightpaths unlocked.
60% riding + mount free at lvl 20
Realm firsts (bosses) award special and exclusive rewards. (click here to see more about it)
Level realm firsts for lvl 60/70/80 that award titles depending on your class and race. Check this page for more info.
Dual Spec available in all expansions and it's free at character creation.
Battlegrounds give experience and are an alternative to normal leveling.
Quest items are 100% drop rate and party-shared.
Players can queue RDF and BG at the same time.
Custom Hardmode system - players can increase the difficulty of the dungeon and receive extra badges.
Attunements for dungeons and raids. (only for specific patches, for example when BWL opens the MC attunement is not needed anymore, basically the attunements from the current patch are removed on the next one)
Blood elves and Draenei available in all expansions
Anti-AFK bg queue system - players who dodge queues or fail to respond to them get deserted.
Automatic Spell Learner. (including class quest spells, epic mounts excluded)