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Rules
of the Game: Rule Design
Games are, at their core, collections of rules.
Behind the pretty artwork and beneath the adept programming, we find
the soul of the game: the rule design.
Chess and Go
Let us begin by considering some of the oldest games: Go and
Chess. The ancient Chinese game of Go looks simple. Players
alternate turns placing black and white stones on a 19 by 19 grid,
trying to surround enemy stones and enclose territory. The rules are
simple, but the resulting gameplay is extremely complicated. Each
play of a stone can affect the safety or strength of the stones near
it. These effects ripple across space (the board) and time (over
many plays). Go exhibits what biologists call “emergent
properties” of complexity that are much greater than the sum of
its simple rules.
Chess has similar properties, but they stem
from an entirely separate set of rules. In Chess, one’s pieces
start in a very cramped position, all in each other’s way. Players
must “develop” their pieces, that is, get them out from behind
each other so they can exert maximum control of the board. The catch
is that the board is extremely small. Once each player develops his
pieces even moderately, they are now in direct conflict with enemy
pieces simply because there is no where to hide on the tiny Chess
board. The overlapping influence of many pieces is only one source
of Chess’s complexity (though that description hardly does the
game justice!).
Marvel vs. Capcom 2
As for more modern games, allow me to yet again reference the
fighting game Marvel vs. Capcom 2. In this game, players pick three
characters, only one of which can be active at any time. The
inactive characters can be called onto the screen to do a preset
“assist” move, which allows the player to attack in parallel
(simultaneously with his active character and with an assist move).
This obvious advantage is offset by the assist character’s extreme
vulnerability. He cannot block, and he must perform his entire move
(which often includes somewhat slow recovery) before leaving the
screen back to safety. The more a player’s assist character is
damaged, the less energy that character will have when the player
switches the assist character to be the active character.
It’s a neat set of rules that all work
together. The ability to attack in parallel creates lots of
opportunity for creative gameplay, and the mechanic has built-in
checks and balances. What’s interesting is that when the game
first came out, a friend of mine asked me if it’s any good. I was
unable to answer. I told him, “The rule design seems to make a lot
of sense, so it has the potential to be good. But it’s impossible
to tell until we all play it more.” Good rule design can ruined by
poor balance, slipshod implementation, bugs, and myriad other
factors.
What struck me most about my friend’s
question was that purely by the rule design, I knew the game had the
potential to be good. It also struck me that although I had
seen all the art in the game, seen all the characters, understood
pretty much all the moves…the entirely of whether the game would
actually be good rested on the shoulders of the implementation, the
balance, the tweaking. The programming was good enough to express
the rule design, and the art was good enough to “look cool.” A
great illustration of the importance (an limits) of design.
Counterstrike
The Counterstrike mod
for Half-life is an even more amazing illustration of rule design.
I’ve been told that this game is currently the most popular first
person shooter, and that at one time (perhaps still) it was more
played online than all other first person shooters combined! And
remember, Counterstrike is a mod of a game, not even a full
game! Here’s another case of programming and art playing only
minor roles in the quality of a game. There are 10 zillion other
mods of Half-life with basically the same programming quality (they
all use the same engine from Half-life of course) and with no worse
art.
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| Counterstrike's
incredible popularity is due to its clever rule design, not
its realism. |
Further consider that I am not a fan of realism
in games, and that despite Counterstrike being one of the most
realistic first person shooters available, I find it by far the most
fun. Why? Rule design. In Counterstrike, you play a 5 minute game
round, then the game resets. If you die, you’re out until the next
round, but you can freely observe everywhere and everyone in the
level as an invisible ghost. There is even somewhat of a metagame
since money (used to buy weapons at the beginning of each round)
carries over between rounds. Counterstrike also features interesting
win conditions asymmetric across the two teams. Rather than just
rack up frags, one team must try to compete an objective (such as
plant a bomb or rescue hostages) while the other team must prevent
the first team from succeeding.
These rules create great pacing. Since the fear
of death is much greater than in Quake (one shot kills, you’ll
have to wait until the next round to play again), every corner and
doorway becomes frightening (see my article on suspense). Tension
builds, climaxes are reached during fast firefights. When you die,
you have a minute of downtime before starting the next round which
can be used as mental rest or as strategic reconnaissance in ghost
mode.
Magic: the Gathering
The trading card game Magic
the Gathering goes the extra mile by being a game almost
entirely about rules. Magic is a (mostly two player) game where each
player tries to reduce the other’s life points from 20 to 0. Each
player has a deck of 60 cards chosen from a set of over 1,000 legal
cards. Decks contain one-time-use spells, continuously active spells
(called enchantments), creatures that can attack the enemy over and
over, and land cards that are the resources needed to play all the
other cards.
There’s
a concrete set of rules governing the game Magic, but the most
interesting rule is the Golden Rule of Magic: any rule
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| This
card lets you prevent the opponent from playing any card you
name! |
printed
on a card supercedes the base rules of Magic. It’s a game about
overriding the rules. One rule is that each player draws one card
per turn. One spell lets a player draw 4 cards that turn. One rule
says that a creature who attacks this turn cannot block an incoming
attack on the next turn. Not only are there creature cards that
allow this, but there are even cards that allow all your creatures
to break that rule forever! Playing Magic--or more specifically,
building a deck designed to abuse the rules in a certain way--is
more like designing a game than playing one. I recommend that every
game designer check it out.
Magic has no programming, and completely
superficial art. It’s a true example of a game being purely rule
design. Or perhaps of rule design completely stealing the show.
There’s another, less known card game called
Flux, which is also a game about changing the rules. It has a
variety of cards that change the win conditions of the game.
Whichever player plays the Pyramid card and the Sphinx card
wins…until I play the card that says whoever plays both the Milk
card and the Cookies card wins! Is the game a satire of games about
rules? Or a satire of itself? I’m not really sure.
Nomic
If you think a game can’t be any more oriented towards rule
design than Magic (or Flux), then I have some news for you. The game
of Nomic is a game explicitly about changing the rules of Nomic.
It’s a game about itself, orders of magnitude more so than Flux.
Nomic has no programming at all, not art, not even any cards. It’s
just a set of “initial rules” which mostly explain how to change
the these rules. The rules are divided into two sets: mutable and
immutable. One rule says that immutable rules cannot be changed.
Another rule says that mutable rules can be changed. Another says
that it’s possible to change a rule from being immutable to
mutable, and vice versa. (So you could demote an immutable rule to
mutable, then change it, then promote it again.) Another rule states
that players take turns and that a turn consists of proposing a rule
change and voting on it in a specific way. A player wins if his rule
change somehow entraps the game so deeply in paradox that play
cannot continue. A player can also win by reaching a certain point
total first, but that rule is mutable and would surely be one of the
first to go!
Don’t forget that all these rules can
be changed. Players could implement rules that each turn also
consists of making a move in another game such as a Chess, and that
winning that game is an alternate win condition for Nomic. Players
could create new classes of rules besides mutable and immutable, or
even modify the rules to make Nomic into another game, perhaps
Monopoly or Tiddly-winks. It’s quite a trick to alter the rules so
radically that no more rule changes are possible, though.
Nomic isn’t quite as addictive as, say,
Tetris, but it’s sure interesting to contemplate playing! It’s
the furthest example of rule design gone completely crazy,
overshadowing the entire game with rules about the game’s own
rules. Let it serve as a reminder that rule design is an important
component of game design…but should not be the only
component unless your goal is to make a game so unusual and out of
the main stream that it’s mentioned only in articles about rule
design. ;)
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