Special raids, one a day that drops lots of scrolls or equipment that drop in all other raids but more frequently because it has 24 hour cooldown, or just resets at x time per day
Skill trees could be cool. one for melle, ranged, healers, or raid buffs / cooldown timers, you only get to choose one tree, points every 25 levels or something
Raiders should have a positioning built into their raiding, why are my archers / healers always competing for front row
they get killed too fast / in range of aoe damage
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