Input randomness

If random outcomes will resolve before the players make their decisions, this is called input randomness. The random outcome determines the context of decisions yet to be made.

This is generally great for strategy games. The prices of goods might be randomized, or the layout of the terrain, or the order of the turn. Then, players must navigate the situation they’re placed in.

In this case, the designer must give the players appropriate tools to overcome a wide variety of challenges. Input randomness paired with a wide variety of tools is the ideal condition for the emergence of discovered play.

Output randomness

If random events will occur after the players make their decisions, this is called output randomness. Output randomness generally determines whether your strategy succeeds or fails.

In these situations, the appetite for risk is a key factor in the player’s decision making. Games with output randomness can be thrilling, but often must be played iteratively in order to be considered games of strategy.

For example, Poker is a game with both input and output randomness. The input randomness is the hand you are dealt, which you know and must use to make decisions. The output randomness is your opponent’s hand, which you must speculate against in order to win.