ToME: the Tales of Maj'Eyal

What do those physical/mental/spell save numbers mean exactly? Are they percentages, like status resists, or what? What is a chance to avoid effect of effect with respective power X, if I have respective save Y?

They measure the level of resistance of your character against attacks of various types.

When you're hit by an attack of that type, the attacker uses an opposing score (usually power of the same type) to determine how effective the attack is. The game then compares both scores and decides whether the attack succeeds, or how well it succeeds.

If the attacker's score is greater than your save score, the attack is more likely to work than if it's less than yours. There is no upper limit on power and saves (though it gets harder and harder to improve them) and larger numbers are always better. Equal power and save scores usually mean a 50-50 chance of success.

What if save is better that power by 10? Less by 10? What chances are then?

If I remember the advanced tutorial correctly, if the defender's save is 10 points better than the attacker's power then the chance of the attack working will be equal to the specific attacker's minimal chance of success. And if power is 10 points higher than defense the attack has that specific attacker's maximum chance of success. This minimum and maximum chance of success differ from one atatcker to another. An educated guess would be that you can expect them to be roughly 30% and 70% for players and typical mobs and higher than that for bosses (the reasoning behind the guess is that default resistance cap for players is 70%, while bosses can have much higher resistance values).

The advanced tutorial is outdated. It used to be that +1 save was +5% save chance, but it got nerfed to 2.5% save chance - now you need attacker's power +20 save to be perfectly immune to their status, and defender's save +20 to be absolutely guaranteed to affect them. Accuracy vs. defense checks work the same way.

Save used depends on the effect that it would cause, and power used depends on the talent being used. For example, Starfall, Stunning Blow, Dual Strike, and Tornado all stun the target, but Starfall uses spellpower, Stunning Blow uses physical power, Dual Strike uses accuracy, and Tornado uses mindpower.

But you have to keep in mind that saves go through a weird "diminishing returns" process, so if some item gives you +4 mind save, then that means that it gives +4 save when you're at 0 save. When you're at 50, maybe it gives you +1 save. (Don't remember exactly.) Additionally, there are a large number of effects that don't actually grant saves (or at least there were in v1.0.0). So I don't feel too bad about being all "lol i dunno" when it comes to my characters' saves