36 / wfmag.cc
For example, rolling one six-sided die gives
me a 50% chance of getting a four or more,
but rolling and adding two dice increases
that to 75% (not to 100%, which is the sort of
probability trap people fall into. More on this in
a moment).
If you roll thousands of dice and count the
results then you’re using statistics, but if you do
the calculations upfront then that’s probability.
In general – and assuming you have someone
confident with these sort of calculations – it’s
easier to work out probabilities than look up
X many thousand results to see the trends.
However, statistics can still be useful for
things that are extremely difficult to work out in
advance. Here’s an example: Say you’re makinga turn-based, tactical football game, where clever
play is key, but you still want some elements of
chance. But where to apply that chance? Should
the chances of a goal being scored be primarily
dictated by each football player’s skill, or
perhaps positioning should be more important?
One way to find out would be to place a
player at position ‘X’ on the pitch and tell the
computer to have that player make 1000 shots
at goal (which shouldn’t take it too long, as it
doesn’t need to draw the graphics, just tell you
the results). That’ll give you a baseline of the
chances of a player with that skill scoring from
that position.
Now you can move position X, change the
player’s skill values, and later maybe introduce
a goalkeeper. By changing only one thing at a
time and running the test over and over, you
work out how much of an effect each of those
elements has on the chances of scoring, and
decide if that’s how you want chance in your
game to work. All of which would be awkward
to work out by calculating probabilities.
One final point about probability is that people
are good at making quick, very rough guesses
(called ‘going with our gut’), but bad at working
out precise odds. We’re also easily overwhelmed
by too many choices and tend to over-value
things we already have, compared to any better
potential rewards we might get. In short, thisROLL WITH IT
If you’re interested in heavily
basing a game on chance, then
I highly recommend studying
board games, because they’re
great at exposing where they
use chance (rather than the way
video games make it hard to see
the ‘dice rolls’ going on behind
the scenes). You can also tweak
elements of board games
to watch how your changes
minimise or exaggerate the
effect of chance. Games like
Las Vegas, Liar’s Dice, 6 Nimmt!,
and No Thanks! all have risk as
their key gameplay element.
In games with elements of
chance, like XCOM 2, a big
part of the gameplay
revolves around how players
can stack the odds in
their favour.
The AI director in Left 4
Dead can be seen as an
evolution of ‘fixed
randomness’, as it ensures
every play session is exciting,
well-paced, and fair.
Skill versus chance: using luck in gamesToolbox