AI in board gamesmeteor

2017-4-7

What’s a board game?

Literally, A board game has two parts: a board, and a game.Sure there’re different boards!

Chess board

Round Table Duel

Where’s the board…?

Why board games?Board games come from the abstraction of real world.

Chess/Go <- Ancient WarsBoard games are foundation of modern video games.

Chainmail -> DND -> Western RPG

History of board games(I)

3500BC - 3000BC: Senet and Backgammon - Oldest known board games2200BC: Go - Ancient Chinese board game800AD: Leaf Game - Earliest card games in China19th Century: Mahjong and Poker - Popular modern card games1933: Monopoly - Fruits of the Great Depression

History of board games(II)

1959: Risk - Modern War Game(Aka American-style board games)1964: Acquire - First Eurogames(Aka German-style board games)1971: Chainmail - Ancestor of DND and West RPG1995: The Settlers of Catan - One of the greatest Eurogames21st Century: Where to go?

Study of Backgammon(I)

Rules2-Players, each has 15 pawns on boardRoll dice to move pawns, which could capture opponent's pawnsMove all of 15 pawns off board to win

MechanicsBetting/WageringRoll/Spin and Move

Study of Backgammon(II)

Expectiminimax TreePerfect, but incomplete informationIntroduce ‘chance node’, takes a weighted averageTree <- Min, Max and Chance NodeMore about Minimax, Alpha-beta pruning and expectiminimax tree.

Future DiscussionSome other games with ‘chance’:

The Settlers of CatanThe Castles of Burgundy

Using ‘chance’ to produce resourcesCould expectiminimax tree be used on the games?

American-style vs German-style(I)

American-style Board Game(also referred to as Ameritrash):Feature a prominent themeEncourage direct conflict between playersHave a significant degree of luck

Some classic titles:RiskTwilight Imperium(Third Edition)Betrayal at House on the Hill

American-style vs German-style(II)

German-style Board Game(Aka Eurogame):Merely mnemonic themeFamily strategyLow randomnessNo player elimination

Some classic titles:Puerto Rico, CarcassonneThrough the Ages, Terra Mystica

American-style vs German-style(III)

How to implement AI for those styles?Ameritrash

All the rules are more or less like BackgammonAI for Risk: Traditional heuristic, MCTS

EuroDifferent mechanics(which may mentioned below) make things different and difficultAI for Catan: MCTS (imperfect -> perfect, without trading)

Popular Card Games(I)

Texas Hold’em (Aka Poker)Betting/Wagering, Player EliminationSet Collection, Bluffing

LandlordAuction/Bidding, Betting/WageringHand Management, Partnerships

Popular Card Games(II)

MahjongHand Management, Set CollectionDraw and Discard Games

BridgeAuction/Bidding, Hand ManagementPartnerships, Trick-taking

Mechanics(I): Auction/Bidding

Auction/BiddingPlace a bid to enhance the position of the game

Typical Games: Modern ArtAuction Types: Traditional/Vickery/English/Dutch

Theory: Auction TheoryResearch on Bidding Hex Game

Mechanics(II): Betting/Wagering

Betting/WageringEncourage or require players to bet money or certain outcomes within the game.

Typical Games: WizardTheory: Gambling and Information Theory

Mechanics(III): Bluffing

BluffingHidden InformationEncourage players to use deception to achieve their aims

Typical Games: Liar’s DiceLibratus and DeepStack

Mechanics(IV): Draw and Discard

Draw and DiscardHands, drawing deck and discard pileDraw and discard to improve your hand towards some objective

Typical Games: Love Letter, RummikubHand Evaluation: A Mahjong example, Mahjong with MCTS and opponent Modeling

Mechanics(V): Hand Management

Hand ManagementReward players for playing the cards in certain sequences or groupsManage your hands means gaining the most value out of available cards under given circumstance

Typical Games: Agricola

Mechanics(VI): Partnerships

PartnershipsOffer players a set of rules for alliances and teamsOften able to win as a team, or penalties are enforced for not respecting alliances

Typical Games: Tichu, Codenames

Mechanics(VII): Player Elimination

Player EliminationMultiple-player games(>2) when a player can be eliminated from the game and play continues without the eliminated player.Doesn’t include 2-player-only games where the goal is to defeat the opponent, e.g, Chess

Typical Games: SanguoSha

Mechanics(VIII): Set Collection

Set CollectionEncourage players to collect a set of items

Typical Games: Ticket to Ride

Mechanics(IX): Trick-taking

Trick-takingEach player plays in turn order one card(or, in some games, a series, such as a pair or straight) from their hands face up onto the table; the group of cards played is named a ‘trick’. Winner captures all cards of the trick

Typical Games: Hearts

Tea break: Spyfall

Family and Party Games(I)

SpyfallSetup: Same place, each player except the spy knows where it is, while the spy knows nothingPlay: QA/Call for voting/Guess(spy)/VoteWinning condition

Spy: guess the correct place, or survive at lastOthers: figure out the spy

Family and Party Games(II)

The Werewolves of Miller’s HollowWerewolves: Pretend to be villagers and kill all the villager at nightVillager: Figure out all the werewolvesSpecial abilities

Family and Party Games(III)

DixitUsing phrases to describe picturesPretend to be the original picture which matches the phrase bestGuess

HowTo?NLPDeduction

Hidden informationBluffingGANPlayer portait

Thank you!