Replayability, Part 2: Game Mechanics
July 3, 2001 Page 2 of 3
Sources of Variety
Variety in a game can come from several places:
Varying initial conditions
Most simple board games like chess, checkers and backgammon start with the same initial conditions every time. Both players have the same number of pieces, placed in symmetric positions on the board. But not all games require absolute symmetry. In the board game Stratego, for example, the players start with equal numbers of pieces of equal strength, but they may set them up in their own areas of the board any way they like. This freedom in the initial conditions creates variety for the players.
Initial conditions can also be established randomly; this is of course the basis of most card games. The deck is randomized by shuffling, and then a certain number of cards are dealt out to each player. Bridge and hearts are good examples of card games that depend entirely on varying initial conditions for its gameplay - all the cards are dealt out, and the players play them as they best see fit.
Chance as a part of gameplay
Even if the initial conditions are identical, a game can include random elements as part of the rules of the game. Backgammon and Monopoly are good examples of this. The pieces start in identical positions, but their movement is determined by throwing dice.
Any card game in which you draw cards from a shuffled deck in the course of play (gin rummy and most forms of poker, for example) is using both random initial conditions and randomness during gameplay to create variety.
In a game like chess, with identical starting conditions and no random elements, what provides the variety is the opponent's gameplay. This usually (but not always) means that a human being is a more interesting opponent than a computer. Computers tend to be programmed with deterministic, number-crunching algorithms to find the best move, according to some metric for measuring the quality of a given move. With a deterministic algorithm, a computer program will always choose the same move in a given situation. In time, human players can learn to take advantage of this predictability; they also tend to find it rather dull.
In a game like chess, with identical starting conditions and no random elements, what provides the variety is the opponent's gameplay.
Human opponents are more interesting because in addition to having varying strategic and tactical abilities, they differ in the degree to which they're aggressive or defensive, devious or forthright, cautious or risk-takers. And of course, you can talk to them. There's a social aspect of playing against other people that is completely absent when playing against a computer, and that tends to make the game replayable even if nothing else does.
A choice of player roles and strategies
If a player can play a game in several different roles, the game will feel different even if its content is the same. The character classes, races, and alignments in Dungeons & Dragons are a perfect example of this sort of thing. You might play an entire computer game as a lawful good human fighter, then decide to replay it again as a chaotic evil elf magic-user. Although you encounter the same people, creatures, and dangers the second time around, your approach to dealing with them will be significantly different, especially if the designers have constructed obstacles that can be overcome by a variety of methods. (Unfortunately, in far too many role-playing games the only method available is "whack it until it's dead." But at least there are a variety of ways of whacking it.)
You can play an enormous game like Baldur's Gate from beginning to end and still not see every location or undertake every quest, particularly if you concentrate on the main storyline and don't allow yourself to get sidetracked often the first time through. This gives Baldur's Gate considerable replayability. It's just so big that it's worth going back and playing again to follow up on adventuring opportunities that you missed the first time around.
You can play an enormous game like Baldur's Gate from beginning to end and still not see every location or undertake every quest.
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