"Of course, nothing is a substitute for extensive training, but sometimes you are forced to work with inexperienced troops."Mass Precision is a third-level order magic spell in Heroes of Might and Magic IV that costs five spell points and increases the ranged attack of all friendly ranged targets by 25%, and also gives the target no penalty for range, walls or obstacles.
The player who prefers ranged attacks covets this spell, and rightly so. The benefits of standard precision are given to all friendly targets, rendering the range-oriented army a force to be reckoned with.
However, you cannot cast this spell on your own army if your hero is wearing the Mind Shield. As it is considered a mind spell, undead heroes and mechanical creatures are unaffected. The Crown of Enchantment can confer on the caster the ability to target some otherwise immune creatures with mind spells.
Note the spell does not ensure the boosted stack will always do full ranged damage. If there are two or more factors affecting ranged damage (such as distance and an obstacle) you might only do half damage (compared to one quarter damage without the spell).