Design pattern Library - Game Mechanics: Advanced Game Design - page 323

It is quite common to implement attrition using two resources, life and energy, instead
of just one, strength. Players use energy to perform actions and lose the game when
they run out of life. When using these two resources, it is important that they be
somehow related. Often, players are allowed to spend energy to gain more life.
Sometimes the relationship between life and energy is implicit. For example, when
a player must choose between spending energy or gaining life, there is an implicit
link between the two because players generally cannot do both at the same time.
In a two-player version of attrition, the game must include other actions, and
games for more than two players often allow other actions that the players can
perform. Most of the time these actions constitute some sort of production mech-
anism for strength, which increases the effectiveness the players' defensive or
offensive capabilities (and thus elaborates the attrition pattern to an arms race
pattern). Most real-time strategy games include all these options, often with mul-
tiple variants for each.
The winning conditions and effects of eliminating another player have a big impact
on the attrition pattern. The winning condition does not need to be elimination,
however. Players might score points, or reach a particular goal outside the attrition
pattern, which automatically widens the number of strategies available. When there
is a bonus for attacking or eliminating players, the pattern can be made to stimulate
the elimination of weaker players.
examples
The trading card game Magic: The Gathering implements an elaborate version of the
attrition pattern. Figure B.11 presents this implementation, although it shows the
details from the perspective of a single player only.
FIGURe b.11
The attrition mecha-
nism in Magic: The
Gathering