1.Prepositional phraseAs a joke. .mw-parser-output .defdate{font-size:smaller}
"You mustn't take what I said so seriously, it was only said in play."
2.Prepositional phraseIn operation, active, currently valid, at play, at work.
"It's hard to tell which physical forces are in play at this altitude.; This deadly scenario with this hurricane is still in play, so please take precaution."
3.Prepositional phraseAvailable to be played according to the rules of the game in question; within the boundaries of the pitch, within the realm of the possible, etc.
"now everything is in play; The ball is in play for an average of just seven minutes out of a sixty-minute game."
4.Prepositional phraseCapable of being won by more than one party or candidate.
"Though the state has not changed hands in 20 years, the latest polls suggest it may now be in play."
5.Prepositional phraseOpen to a takeover bid.
"Despite the best efforts of the executive committee, it seems the company is now in play."