The Quest for Brevity

After adding a rule for sleep deprivation based on the encumbrance rule, I figured it made more sense to express this as a single mechanic. I then realised it could then be applied to all manner of setbacks which gave rise to the idea of a "penalty box".

I was also unhappy with the idea of deducting a number from the dice roll before adding modifiers. It felt like one step too many and adjusting the challenge tier was a much neater way of reflecting increased difficulty for an impaired character.