A normal play convention in a game is the method of determining the winner that is generally regarded as standard. For example:

• Preventing the other player from being able to move
• Being the first player to achieve a target
• Holding the highest value hand
• Taking the most card tricks
  Trick-taking game
  A trick-taking game is a card game or tile-based game in which play centers on a series of finite rounds or units of play, called tricks. The object of such games then may be closely tied to the number of tricks taken, as in plain-trick games such as Whist, Contract Bridge, Napoleon, Rowboat, and...
  
  

In combinatorial game theory

Combinatorial game theory

Combinatorial game theory is a branch of applied mathematics and theoretical computer science that studies sequential games with perfect information, that is, two-player games which have a position in which the players take turns changing in defined ways or moves to achieve a defined winning...

, the normal play convention of an impartial game

Impartial game

In combinatorial game theory, an impartial game is a game in which the allowable moves depend only on the position and not on which of the two players is currently moving, and where the payoffs are symmetric...

 is that the last player able to move is the winner.

By contrast "misère game

Misère game

Misere or misère is a bid in various card games, and the player who bids misere undertakes to win no tricks or as few as possible, usually at no trump, in the round to be played...

s" involve upsetting the convention and declaring a winner the individual who would normally be considered the loser.