It's been mentioned, but anytime the DM says
DM: PC, make a *fill in le blank* check.
PC: Err... *Result*
Dm: Continue.
PC's: GAHHH!
orrrrrrr (this happened not too long ago, I was DM )
DM: Have you gone yet this combat? No? *Check's sheet* That's a lot of d6's... *rummages through dice bag*