Immune / Resist / Weak

Right now a value of 0 is no different. A negative value means you take extra damage. The value is a percentage. i.e. -100 to psychic attacks makes you take double damage from psychic attacks. A value of 100 means you're 100% resistant to it, so you are immune to damage.

No clue what to do with this.

Maybe...

Sanc is 50% damage reduction against anything (except psionic)... What if you have to get at least 50% resistance in something before it gets better...

For example:

You have 30% resist blunt... but then you cast sanc... sanc just changes that to 50% resist blunt...

If you have 55% blunt resistance, and cast sanc... you still are only resistant to blunt 55%