One of the cornerstones of a good group is, in my experience, motivation. Not only player motivation, but character motivation. Far too often I’ve seen players writing elaborate backstories that completely omit what they are hoping to accomplish by risking their lives in the dungeon, and why they are doing so with the other PCs. I like how DW pushes this to the forefront, however, in doing so it also creates certain suppositions upon the game world.
When you grab a class playbook, you introduce the trappings of that class’ gimmick into the world. If someone takes the Wizard, there’s going to be magical things to see and do, for example. Some of these things can be added more easily than others though. “Magic exists” is a common trope that is taken for granted, so it’s easy to put it into the game. You want to play the Fighter? Well, now there’s monsters that need killing. Again, something that doesn’t rock the boat too much.
However, some of the more specialized classes bring with them more baggage, and this may carry with it assumptions about the game that may be harder to integrate. The Warlord that I have been working on carries with him the assumption that the world is, or at least recently was, at war. It makes a world at war part of the global backstory, and it doesn’t consult anyone else on the matter. I worry that these characters who either come with lots of baggage or who have nebulous or spotlight-hogging motivations can pull the group apart.
Just a bit of a ramble. What do you think, internet?