The Grunt is a basic infantry bot that's cheap to build, and can quickly devastate poorly-defended expansions, artillery units, and even isolated Commanders. It also fills a scouting role, gathering intel while easily killing enemy scout units like Ticks.

A small force of Grunts can easily kill an undefended Commander.

It is armed with two light lasers that have slightly greater range than the Pawn's guns, so you can easily take them out by "kiting" them (move back and let the Pawns come to you).

Grunts tend not to stack up very well vs. Light Tanks, which easily outpace them and last longer then they do, allowing the tanks to either pick them apart over time or blow right through them.