grubby shoot: military (primarily mercenary) slang for a mission or contract which pits them against a sufficiently low-tech opponent (q.v. grubby, slang for low-tech locals) that the conflict is hopelessly one-sided and victory requires little or no effort.
Reputable mercenaries and regular military units tend to loathe grubby shoots, as they lack all dignity, honor, and opportunity for valor. Their commanders also note that they have a strongly deleterious effect on morale and troop quality, and thus avoid taking such missions – especially for the long term – whenever possible.
Unfortunately, there are plenty of disreputable mercenaries and militaries out there, usually amateur and pillage- and atrocity-prone, and more can often be created ad hoc by arming the local grubbies with advanced weapons.
– A Star Traveler’s Dictionary