Complex sentence: The defendant may also assert counterclaims for damages or equitable relief against the plaintiff, and in the case of "compulsory counterclaims," must do so or risk having the counterclaim barred in any subsequent proceeding.
Split into simpler sentences: The defendant may also assert counterclaims for damages or equitable relief against the plaintiff. For example, in the case of "compulsory counterclaims," the defendant must assert some form of counterclaim or risk having the counterclaim barred in any subsequent proceeding.