|Primary skill symbols which recur almost in the same form throughout the game.|
Attack skill together with defense are the main factors affecting the amount of damage creatures deals under the hero's command. A hero's attack skill value is added to each of the stack's attack rating, increasing the amount of damage they can inflict in combat.
Defense skill works in similar way to attack skill. Heroes' defense skill is added to the defense rating of each of the creatures in their army, which decreases the amount of damage they take from enemy attacks.
Power skill (or sometimes spell power) is the main factor for duration of the spells and the amount of damage they cause.
Knowledge skill determines the maximum amount of spell points a hero may have. It is calculated by multiplying knowledge with 10, so knowledge of 13 would give a hero a natural maximum of 130 spell points. With the Intelligence secondary skill, this natural maximum can be increased up to double. Additionally, visiting a mana vortex or a magic spring hero can temporarily double the spell points, which means that with expert intelligence, the maximum spell points will be quadrupled from original amount.
By default, all heroes have at least one point in every primary skill. However, a map-maker can set the starting skill to 0. In that case, the hero will look and function as if the value would be one. When the hero receives the first point to the skill, he will still have only one point in it, but after that the points accumulate normally.