Does every point of intelligence matter?

[Handel]

I play as a mage (my first serious game) and I am absolutely sure - every point of INT increases the damage with 10%; every 7 points give 10% additional bonus; so with 9 points if INT you get double damage. Minus the enemy resistance of course. I checked it at the very begining. Non-modified (with 0 INT ) fireball makes 155 damage in the central hex; with 1 INT it makes 170 damage which is exactly 10% increase (rounded down).

INT increases the damage and from spells like "mirror pain". The basic value of the damage is percentage from the damage dealt by the enemy in the previous turn. In this case what the INT makes is to increase this with 10% FROM THE BASIC VALUE for each point of INT. So if the basic value (for example) is 60% then each point of INT increases it by 6% Don't know if any enemy resistance counts when you cast "mirror pain". The magic resistance if any should be counted but don't really know.