Guile is similar to intelligence, but it's got a bit more of an 'underhanded' sting to it. Technically is your 'combat intelligence' or 'cunning aptitude', and directly governs over Critical Damage, along with being the primary scaling for Daggers. Secondarily, it might be necessary for Ranged weaponry.
Furthermore, like Skill, Strength and Luck, Guile is an essencial stat that aids on making basic attacks more deadly, but only if they critically hit. And for mages or 'autohitting skills' users, it has a small use, of not only for Lightning Critical's damage.
- Increases ACID ATK by 1 per 1 point.
- Increases Flanking bonus by 1 per point.
- Increases Critical Damage by 1% per 1 point.
- Increases Skill Pool size by 1 per 5 points.
- Decreases Farshot Penalty by 1 per 5 points. (IE, at 40 Guile, the penalty is -2 Hit per tile instead of -10).
Pro Tip: Having a minimum of 10-15 GUI will give you +2/3 free skill pool slots, so always make sure your GUI ends with an even '0' or '5' (i.e 10 GUI, 15 GUI, 20 GUI), as every 5 points in it equals to +1 skill pool slot.