gdc canada may 2009 joint work with richard garfield and skaff elias k. robert gutschera senior game...
TRANSCRIPT
GDC CanadaMay 2009
Joint work with Richard Garfield and Skaff Elias
K. Robert GutscheraSenior Game DesignerThe Amazing Society
Luck, Skill, and Hidden Information
Lessons from the World of Paper Games
Outline
What is Luck? Luck vs. Skill Sources of Luck Pros & Cons of Luck Hidden Information
Defining Luck
For our purposes, luck (or randomness) in a game is uncertainty in outcome.
So all games have some luck. Not necessarily coming from dice, cards, random
number generators, etc.
Even Chess Has Luck
Outcome of a chess game is uncertain.
Elo measures it. E.g. if my rating is 1800 and yours is 1870,
you have a ~60% chance to win.
Randomly Beating Kasparov
For an extreme case, consider trying to beat Kasparov by playing randomly.
Chance to win: 1 in 30^50. Win NY lottery 7 times:
1 in (60^6)^7, about the same.
A very small chance − chess has less luck than other games.
Example: Die-Rolling Chess
Two players compete by rolling 1 die. 1-2: first player wins 3-4: second player wins5-6: play chessAll the skill of chess, but a lot more
luck.
Luck vs. Skill
low skill high skill
low luck tic-tac-toe chess
high luck slots poker
Luck and skill aren’t opposites; they’re orthogonal.
And Yet…
Surely there’s some relationship between luck and skill.
What is it?
The Skill Chain
Consider a chain of players, each beating the next 60% of the time:
What does the length of this chain measure?
wins60% vs.
wins60% vs.
wins60% vs.
wins60% vs.A CB
The Skill Chain, II
This is just Elo! For chess, the length is about 30. But for die-rolling chess, it’s about
10 (harder to win 60% of the time!)
Adding luck compresses the skill chain!
Connecting Skill and Luck
Chain seems to measure skill (more skill => longer chain)
But in fact measures returns to skill.
And so, very roughly:Returns to Skill = Skill – Luck
Sources of Luck
Explicit randomizers (cards, dice, RNGs)
Simultaneous choices (e.g. RPS) Human ignorance
Combinatorial (e.g. chess) Deliberate secrets (e.g. xword puzzles)
Luck: the Good
Increased range of competition Something to blame losses on Increased variety of gameplay Catchup mechanism Adds psychological interest
Luck: the Bad
Luck can be confusing. People are bad at probability Randomness can conceal feedback needed
to learn a game’s strategy
People like to feel they are masters of their own fate.
Historically, though, people tend to prefer games with more luck.
Luck: the Ugly
Experienced players may dislike luck because they think they’ll win more if the game has less.
This is both true and false. Designers are experienced, thus prone to
this trap.
Sometimes you should listen – but sometimes you shouldn’t.
Hidden Information
Things players don’t know: Private info – One knows, others
don’t. Special case: No players know, i.e.
uncertainty, i.e. luck!
Luck & Hidden Information Any source of luck is a source of HI
(the “special case”). Some kind of luck is needed to
generate hidden information. Sometimes private information
generates luck (e.g. RPS).
So the pros & cons of hidden information are very similar to those of luck.
Luck: One More Good
Luck, especially private info, can control calculation by decreasing the rewards to calculation.
Examples: die rolls in minis vs. chess random damage in an RTS dummy in bridge (reverse e.g.) secret victory points in German
board games
Luck Players Will Accept
Simultaneous choices, private info tend to be accepted over explicit randomizers.
“Pre-plan luck” over “post-plan luck”.
Entrenched audiences are tough. New platforms are an opportunity.
Conclusion More luck doesn’t mean less skill! Adding luck to a game can be a
good thing. How you add it, and who your
audience is, can make all the difference.
Questions?