I'm trying to come up with a unique weakness that dwarves (or dwarfs, if you prefer) in D&D-style games could suffer from, as a way to differentiate them from humans, elves, and halflings. I'm trying to refine my house rules for separating race and class in LotFP, and I'd like something interesting to offset their various advantages a bit.
I've flirted with a few ideas so far: making them allergic to sunlight and/or open spaces, making them roll on some kind of Dwarven Madness table at character creation, making them near-sighted, making it harder for them to heal somehow...but I'm having trouble figuring out the mechanical details of how such things would work. Plus I bet there are people out there in OSR Land who will have some awesome ideas.
Preferably, the weakness would be biological, psychological, magical, or some combination thereof. Something that complicates the life a dwarf PC in a more in-depth and fascinating way than, say, a -1 wisdom penalty.
So, anyone have any suggestions?
EDIT: Results are HERE.