During combat, Holy Bonus increases the Melee Attack Strength, Defense and Resistance scores of all friendly units on the battlefield by a set amount. This amount is not reported in-game, but this wiki adds the size of the bonus after the name of the ability to indicate this, rendered as "Holy Bonus +1", "Holy Bonus +2", et cetera.
Bonuses from Holy Bonus do not stack. Therefore, if two units possess this ability, only one (with the highest-strength ability) applies its bonus to all friendly units.
There are only 3 units in the game that possess this ability. One is a Normal Unit, while both others are Fantastic Creatures from the Life realm. It is not possible to add a Holy Bonus to any unit that does not already possess it.
In the world of Master of Magic, divine favours are by far not uncommon. The gods, and particularly the god of the Life realm, may reward their followers' piety by augmenting their combat abilities - conferring not only providence but also great strength. The very presence of some divine or particularly-pious units is enough to ensure that an entire army wins these favours.
During combat, while a unit with Holy Bonus is alive on the battlefield, it will add a certain bonus to the Melee Attack Strength, Defense and Resistance scores of each and every living friendly unit, including itself.
The bonus equals the strength of the Holy Bonus ability. For example, if a unit has Holy Bonus +1, each and every friendly unit on the battlefield (including itself) receives +1 Melee Strength, +1 Defense and +1 Resistance.
As a result, each and every friendly unit becomes more deadly in combat, harder to kill, and harder to affect with Curses and other ill effects. Though bonuses from Holy Bonus are usually very small, they can be very significant - and the greatest benefit is that they apply to all friendly units.
If the Holy Bonus unit dies or is removed from combat, its bonus to all friendlies is immediately lost. Note also that this bonus applies only during combat: the unit does not raise its own attributes nor the attributes of any unit in its army stack while traveling on the overland map.
Holy Bonus does not stack. If there are several units with Holy Bonus fighting together in the same army, the game will pick the one with the strongest Holy Bonus ability and apply bonuses only from that ability. For example, if one unit on the battlefield has Holy Bonus +1, and another has Holy Bonus +2, then only the +2 bonus is applied.
The check to see which unit has the best Holy Bonus is done constantly, so if any such unit dies, the bonus is immediately recalculated. Taking the previous example, if the unit with Holy Bonus +2 dies, the unit with Holy Bonus +1 is now the strongest on the battlefield, so all friendly units now get +1, +1 and +1 instead of the +2 bonuses they received previously. If that unit dies as well, friendly units no longer receive any bonuses.
Units with Holy Bonus Edit
Holy Bonus +2 is the highest possible bonus. There is no unit with a higher Holy Bonus in the game.
Acquiring Holy Bonus Edit
There is no known method by which to acquire Holy Bonus for a unit that does not possess it by default. There is also no way to increase the strength of a unit's Holy Bonus ability.