Expendable
If all friendly Skaven models engaged in a combat have this rule, friendly Skaven units may target the engaged enemy units in that combat during the Shooting Phase. Resolve all rolls to hit as normal. Then, using all failed to hit rolls, roll to wound on a unit with the Expendable special rule engaged in the combat chosen by your opponent.
If firing with a model using a blast template, centre the template over a fighting rank so that it touches both friendly and enemy models as equally as possible with as many models as possible. Roll to scatter and resolve the attack as normal.
If using a Magic Missile to target an enemy unit engaged with a friendly unit with this rule, failed casting rolls (but not successfully dispelled rolls or miscasts) count as successfully cast on a friendly unit with the Expendable special rule engaged in the combat chosen by your opponent.