Gamesmanship
Not a defined legal term; courts use it to describe tactics that exploit procedure to gain an unfair advantage instead of resolving the dispute on the merits — for example, hiding evidence, filing to delay, or ambushing an opponent. The Federal Rules are to be construed, administered and employed to secure the just, speedy and inexpensive determination of every action (Fed. R. Civ. P. 1), and courts can sanction abusive conduct under rules such as Fed. R. Civ. P. 11, 26(g) and 37.
