A counterclaim flips part of the case: instead of only defending against the plaintiff's allegations, the defendant asserts its own cause of action against the plaintiff, litigated within the same proceeding. Procedural systems typically distinguish compulsory counterclaims — those arising out of the same transaction or occurrence as the plaintiff's claim, which generally must be raised now or be lost forever — from permissive counterclaims, which may be raised even if unrelated.

The compulsory/permissive line matters enormously in practice. A defendant who sits on a related claim and later tries to file it as a separate lawsuit can find it barred, because the whole point of the compulsory-counterclaim rule is to force related disputes into one proceeding rather than litigating the same transaction twice. A permissive counterclaim, by contrast, is a strategic choice — the defendant can bring it here or save it for later.

Juricratic models a counterclaim as a second claim track inside the same matter, with its own elements, evidence, and dials, rather than as a footnote to the original complaint. That lets a user simulate the matter the way it will actually be litigated and settled — as a package of offsetting claims — instead of only modeling the plaintiff's exposure in isolation.

Defendants use counterclaims to convert a purely defensive posture into offensive leverage, which can materially change settlement dynamics — a defendant facing a claim plus asserting a real counterclaim negotiates from a different position than one only trying to minimize a loss. Counsel evaluate early in the case whether a related claim is compulsory (and therefore must be raised now) to avoid forfeiting it.