Design pattern Library - Game Mechanics: Advanced Game Design - page 324

In Magic: The Gathering , players can play one card every turn. These cards allow
players to add lands, summon creatures, cast spells to heal, or deal direct damage to
their opponent or their opponent's creatures. But all actions except playing lands
cost mana (magical energy). The more mana players have, the more they can spend
each turn and the more powerful actions they can play. Creatures will fight other
creatures, and when there are no more enemy creatures, they will damage the oppo-
nent directly. Players who lose all their life points are eliminated from the game.
Magic: The Gathering is an example of a game that implements attrition using sepa-
rate resources for life and energy (or in this case, life and mana).
The different gameplay options in Magic: The Gathering illustrate how attrition can
work differently. Direct damage briefly triggers a drain. As its name implies, it is fast
and direct. On the other hand, summoning creatures activates a permanent drain
on the opponent's creatures and life. The effects usually are not as powerful as direct
damage, but because they accumulate over time, they can be quite devastating. The
cards in the player's hand determine which options are available to him and exactly
how powerful those options are. Because players build their own decks from a large
collection of cards, deck building is an important aspect of Magic: The Gathering .
The most obvious way to implement attrition is in a symmetrical game. However,
many single-player games and even certain types of multiplayer games use asym-
metrical attrition. An example of asymmetrical attrition can be found in the board
game Space Hulk in which one player, controlling a handful of space marines, tries
to accomplish a mission while the other player, controlling an unlimited supply of
alien “genestealers,” tries to prevent that. The genestealer player tries to reduce the
number of space marines to stop them from accomplishing their goals and wins
when the genestealers have destroyed enough space marines. The space marine
player usually cannot win by destroying genestealers but must keep the number of
genestealers under control to survive, because the genestealers become more effec-
tive as their numbers grow. Figure B.12 is a rough illustration of the mechanics in
Space Hulk .
FIGURe b.12
asymmetrical attrition
in Space Hulk