Reducing Will against User

[Anaraxes]

Pricing this trait is a time to recall that thread that runs through the design that PCs can and will arrange events to their advantage; conversely, most players will choose synergistic abilities and flog them at every occasion. So, character point prices aren't inevitably symmetrical on positive and negative versions of traits, and the Accessibility cost chart isn't remotely the same thing as percentage of time you get to use an ability.

So, while noting the point cost of the affected attribute is a good observation, the answer unfortunately isn't really as simple as going for the tidy 1% per 2 CP of attribute formula.

"Reduce Will" is nearly always going to be used in the context of improving the Contest for some other ability built to have a Will resistance. (The previously-mentioned Mind Control being a good example. That doesn't just remove an enemy, it switches it to your side, essentially doubling its power in combat, plus all of the non-combat uses of such abilities for information-gathering, infiltration, and deception.)

In that sense, reducing enemy Will is more like increasing the character's attack value with Reliability and the like. But it's generally even more effective because of the Rule of 16, plus the way the 3d6 probability curve works, reducing the enemy's Will of 8-12 produces a bigger skew in the outcome, point for point, than increasing the attacker's skill of 12-16 (at least!).

I'm okay with -5%, as reducing Will is less broadly effective than reducing IQ or DX. But it does seem to me to be in the same focused-but-exploitable category of ST or HT.