Usability testing is on the increase led by companies like PlayableGames and Vertical Slice in the UK, and Microsoft Games Studios having offered their gameplay lab services to their exclusive developers for Xbox from before 20031. Yet it can be regarded as expensive, troublesome to organise and just a distraction from making features for a game product.

It doesn’t have to be.

MMOs are games where you play combat primarily in the user interface rather than the game world.
I think this is best realised in the classic ‘standing in the fire’ error of new raiders: essentially people stand in the fire because it is an element of playing in the game world, where levelling-up has trained those players to instead play in the interface. Combat is in the cooldowns; you watch timers, health bars, debuff bars, and only when you get to raiding or the more ambitious small group dungeons do you need to start looking into the game world too, in order to step out of the fire, dodge the laser beam, jump over the furious shrew of ruin.