1.
MetaBoard: a framework for board
games.
By Laura Risani (alias) with the
collaboration of Stéphane Ducasse

2.
Motivation
Games like
•PacMan
• Tetris
•Sokoban
•Snake
•Miner
•SameTile
•Atomic
•BoulderDash
A tiled space through which pieces are moved
according to some rules

3.
Boardician’s design metaphor
There is a board on a table, a post-it of game data
attached to it, players sitting around and a director
standing.
He says 'play' successively to each of them and, as a
consequence, they according to their thoughts (play-
conditions) modify other players' thoughts by saying
things to them and modify the board/post-it with
their hands.

4.
board
data
play-
conditions
#play
director
player
player
player
player

5.
BGPlayer
BGDirector
BGData BGUserInterface
BGBoardSpace
BGBoardPlace
BGWall
BGFloor
BGMovableItem
BGSteadyItem
<PlayCondition>
BGBoard
BGPosition
*
*
*
*
BGHuman
BGPointer

6.
•BGPlayer : action of modifying game’s board/data/players'
play-conditions when
1. receiving #play
2. receiving other msg to do some work related to its
playing purpose
Tell #nextPlayer.
•<PlayCondition> : anything that conditions how a player
behaves when receiving #play (like
BGDirection : BGDown, … ;
BGPlayState : BGOver , BGPaused, … ;
BGUserInput: BGClick, BGKeyStroke). Not necessarily directly
known by the player.
•BGHuman : action of modifying (…) because of user input.

7.
•BGDirector : action of directing game flow. Initialize and
know the things that made up the board game. Loop while
game not over : decide who plays next, send him #play.
•BGBoard : board’s space and items placed at it.
•BGData : game data that doesn't belong to any particular
object (like lives, score, ... )
•BGUserInterface : handling of user input/output.
•BGFloor can hold any type of BGBoardItem
(BGMovableItem, BGSteadyItem), while BGWall doesn’t
accept any

8.
A possible workflow
To implement a game with the framework
1. Define game's director (subclass of BGDirector) and
then define/implement successively what is needed
in each msg sent from within BGDirector's msg
#initialize.
2. Run game sending 'BGDirectorSubclass new play'
and adjust details according debug windows.
3. Add enhancements (menu, settings, … )

9.
Example : Mines (MI-)
BGFloor
MIBoard
MITile
MIMine MINumber MIVoid
BGBoardSpace
MICoverState
MICovered
MIUncovered
MIFlagState MIFlagged
MIUnflagged
BGBoard
*

10.
BGData MIData
BGPlayer
MITileAction
BGHuman MIHuman
BGDirector MinesGame
•MIData: mines left, seconds spent playing.
•MITileAction: action of doing something on a tile (toggle flag /
uncover) and carrying on its consequences. It’s play-conditions are
the pointed MITile’s MICoverState and MIFlagState.
( 1° )
( 2° ) MICoverState
MIFlagState

11.
Example : Tetris (DP-)
BGSteady
Item
DPBoard
DPSquare
DPPiece
BGBoard
BGMovable
Item
DPPieceLayout
*
BGData
DPData
•DPData: number of completed lines.

12.
BGPlayer
DPPieceMover
BGHuman DPHuman
BGDirector TetrisGame
•DPPieceMover: action of moving current piece. It’s play-condition is
aBGDirection.
•DPPieceDropper: action of dropping current piece (if not bottomed
periodically drop it, if bottomed add it to board and drop a new one).
It’s play-conditions are aBGTimedState and the BGPosition of the
board where new pieces are first dropped)
( 1° )
( 2° )
BGTimedState
BGDirection
DPPieceDropper
( 3° ) BGPosition

13.
Example : Pacman (E-)
BGBoardSpace
BGFloor
BGMovableItem
BGSteadyItem
EBoard
*
*
EEater
BGBoard
EBiFloor
ETeletransporter
ETriFloor
EDirectedFloor
EBullet
EBigBullet ESmallBullet
EScoreItem
EMonster
BGData EData

14.
BGPlayer
EEaterMover
BGHuman EHuman
BGDirector PacmanGame
( 1° )
( 2° )
BGTimedState
BGDirection
EMonsterMover
( 3° )
EScoreItemPlacer
( 4° )
BGDirection EAttitude
EVulnerability
EMoveConseq
uencer
, ,
EPositionSituation
EEaterAtBullet ,
EEaterAtEmptyFloor ,
EEaterAtMonster ,
EEaterAtScoreItem ,
EMonsterNotAtEater

15.
•EData: lives, score.
•EMoveConsequencer : action of carrying on consequences of
moving an EEater / EMonster. Play-conditions: BGPosition,
EEater/EMonster , EPositionSituation subclasses.
•EEaterMover : action of moving an EEater and carrying on
consequences. Play-conditions: BGDirection.
•EMonsterMover: action of moving an EMonster and carrying on
consequences. Play-conditions: BGFloor subclasses, BGDirection,
EVulnerability, EAttitude.
•EScoreItemPlacer : action of placing/displacing a EScoreItem on the
board. Play-conditions: BGTimedState.

16.
Other example games : Sokoban, Snake, SameColor.
More info at
http://boardician.blogspot.com/2015/07/metaboard.html
Questions? Comments? Suggestions? Mail me at
laura.risani@gmail.com
Thank you !
<3