Just an idea...

Spend bonus points on a *one time* boost for offense or defense.

i.e., let's say you spend 4 points and get a 25% boost to offense on your next attack. Or a 25% boost to defense on your next defend.

The boost is high because it is a one-time thing, vs. the standard permanent defense bonus. This is more like a "boom" event for off/def.

lol how would we know if the defender has defence bump up by 25 percent? do we have to overseas 30 percent now

5

I think the point would be an element of surprise.

Although you could make it detectable in a spy op.

for 25%? maybe 16 bonus points :p