What are the essential differences you need to know about when going from 10 to 25 man Ulduar? Here are the changes. This does not explain hard modes, except on a few.
> Read the full guide here
I assume you have watched TankSpot videos and read strategy guides, so this does not cover those basics.
In the 25-man column I’ll describe if the ability or your strategy needs to change. If something simply hits harder, I’ll still say ‘no change’. Bosses do more damage and have more HP, which I don’t list either.