nonmandatory (adjective) discretionary: open to choice
Sinonime: antagonism, athletic event,
bout, candidacy, championship, clash, concours,
contention,
controversy, counteraction, do or die, dog eat dog, emulation,
encounter,
engagement, event, fight,
game, go for it, go for the gold, horse race,
jungle*, match, matchup, meeting, one on one, one-upping,
opposition, pairing off,
puzzle, quiz,
race, racing, rat race,
rivalry,
run, sport,
strife,
striving,
struggle, tilt, tournament,
trial, tug-of-war, warfare
Antonime: nondiscretionary