Discussion about Heroes 4.

As I recall, it is considered a bonus (skill) of the hero who has the higher value. The bonuses from artifacts are added to the skills of the player who possesses them. However, there are cases where the bonuses from artifacts are added to the maximum skill value, regardless of which hero possesses them. Check the reference guide – the sections on morale/luck, attack/defense, and speed/movement range in battle – I’ve explained it in more detail there.