From the wiki: https://masterofmagic.fandom.com/wiki/Prayer
Having this included makes Prayer way, way OP, especially considering that it is only Uncommon and cheap to cast. I had a stack of Paladins defeated by stack of Regular Gnoll spearmen, except I had a single figure of a single unit left, because the AI had Prayer in effect. That was essentially the only thing they had going for them. So, Spearmen with Prayer can defeat Paladins. Come on. I've been playing 1.5 for years and Prayer is very good in that, but its not like this. This is crazy. The debuff should be removed.While Prayer is in effect, each and every enemy unit on the battlefield receives a -10% To Hit malus to their Melee Attacks. That is, every time they perform such an attack against a unit affected by Prayer, including during Counter Attacks, the success chance of each die of their Attack Roll is reduced by 10%. While this does not affect their potential damage, it does decrease their average "raw" Melee Damage output by an amount proportionate to their Melee Strength. Other Attack Types are not affected.
It should be noted that this effect is removed from the game starting with the unofficial Insecticide patch. Examination of the game code has led multiple patch-makers to the conclusion that this is actually not an intentional benefit. It is most likely left over from an earlier stage of the game development, where Melee Attacks were handled differently from other Conventional Damage types (hence why the effect only triggers for Melee Damage).
