keinritli 'play ritual'; "to play a game" ritlykei 'ritually-play'.
kelci (x1 plays with x2) can be used for any unstructured or structured, pretending-activity; while these words emphasize the rulebound nature of games. This might be an important distinction in future discussions of constructed languages, & even the Sapir-Whorf hypothesis...
keirterjva (x1 is a game in which (moves?) x2 are prescribed by rules x3) is an abstract game, as chess is a game and volleyball is another game. A game as in "the chess players played two games" is keirterjvi.