Player Versus Player/Playing With

Basic Trope: In a videogame, players are the enemies of the other players.
 * Straight: A game has a mode where two or more players oppose each other.
 * Two players have a match in an arcade fighting game.
 * Justified: A reason is given ingame for why the characters are fighting.
 * Jim and John are arch rivals according to the story of an arcade fighter. Different players take control of Jim and John.
 * Inverted: A game doesn't include a PVP feature. Only one player plays at a time. Alternatively, an game where the players only work together, and can't hurt each other in any way. See Co Op Multiplayer.
 * A single player arcade fighting game.
 * Environment vs environment. Players(?) can only watch as NPCs duke it out with each other.
 * Subverted: A game has a genre where players expect PVP as part of the standard feature set, but it isn't included.
 * An arcade fighting game doesn't include a PVP feature. Players expect a PVP feature in the fighting game genre.
 * Doubly Subverted: A game looks like it's going to be single player only in a genre where it's expected. But there is one (or several) stages where a second player can join in and help out.
 * Most of the levels in an arcade fighter are played solo. But a second player can join in on Stage 3.
 * Untwisted: A game has a genre where players expect PVP as part of the standard feature set and it isn't available at the start but it becomes available later.
 * Players cooperate to beat an arcade fighter. After the final boss is defeated, there is one last level where the players fight each other.
 * Zig Zagged: A selection of levels in a videogame are PVP, but not all of them.
 * In an arcade fighter, a players fights another player if available. They fight the computer if no other player is available.
 * Averted: A game does not include a PVP feature. Gamers don't expect a game of its genre to include one.
 * A long format RPG doesn't include a PVP feature. Players of that genre don't expect a PVP feature.
 * Enforced: For certain game genres, gamers expect a PVP feature.
 * A PVP feature is included in an arcade fighter because gamers expect it and all companies in the arcade fighter space include a PVP feature in all of their games.
 * Necessary Weasel: See enforced.
 * Exaggerated: A game where hundreds of players play simultaneously. See also Massively Multiplayer Online Games.
 * An arcade fighter allows four players to play simultaneously. Two is typical for the genre.