I play various political simulations online (basically, you choose a country and you interact with other countries). Is it a sin if, as part of the intrigue of the game, one lies? For example, playing as Germany in one of these games (called Nations), I launched a secret attack on Iran. Later, I played it up as though the craft that launched the attack were stolen, thus lying in the game, but it is a part of the intrigue of the game (just like IRL leaders cover things up and try to deny things in order to cover themselves).
Is that a sin? No money is involved in these games.