Fatigue 100- ?

[thejeff]

You have an increased chance of criticals with any fatigue. You pass out at 100 and fatigue converts into damage over 200.
Mages are perfectly willing to cast spells that cast more than 100 fatigue, or put them over 100.
It does not have to be the first spell.

All the minus sign tells you is that fatigue cost is reduced by having a higher path level than needed. You'll notice that all spells have this.

Note that 100 fatigue also means 1 gem. You will actually take slightly more than 100 based on encumbrance.

Your mage will also happily burn extra gems to keep his fatigue down.