Each character, whether the hero or an opponent, may perform special attacks and cast spells. This requires special Ability points and obtaining special Abilities/Spells (Skillbooks). Depending on how many ability points your character has, you can learn a limited number of spells. Also, thanks to this, the penalty to Action Points drops, for using the Ability, in the case in which the character has a lower Ability level than required by the spell used - per every level below the required one, the number of AP increases by 2. Some of the abilities require an appropriate character level to be used and, until it is reached, a given spell/ability cannot be obtained.
The number of spells/abilities that can be learned
The maximum ability level
Abilities also depend on certain attributes where, e.g. for the archer it is agility and for the mage intelligence. They should be developed at a par with the character development - they have their effect on appropriate modifiers - hits, receiving of an effect (if the ability can provide it, it raises as the attribute goes up).
After the spell is used (does not concern abilities), you need to wait for a certain period of time before you can use it again (Cooldown). This parameter depends on the amount of intelligence, which decreases cooldown by 1 turn, per each 2 points of that Attribute.