Heroes 5.5 WarGame Edition - Tactical Edition.

For the "Warlord" and "Shaman" classes, the spellbook will look like a regular one, but it will still only record spells.

I meant the same bonus, but one that would depend on magic.

Why introduce an additional dependency on magic? Magic is already strongly emphasized due to its distribution into another random stat (temporary bonuses), plus the added ability to upgrade the "Magic Resistance" perk (50% of magic goes towards reducing the opponent's magic), which, in combination, could lead to a situation where it would be almost beneficial for an Orc to increase their magic stat with artifacts, without any additional boosts.