Representing Board Game State — The Players
This is the third in a series of posts describing a boardgame state modelling language. The previous posts dealt with the board, the cards and the pieces. This post deals with the players.
The Players
From one perspective the concept of having players in a boardgame isn’t very interesting from a modelling perspective. You have 1 to many players and that is it. It is only when you start looking at the relationships players have with other game concepts that things get a little more interesting.
The first concept I want to look at is the concept of “ownership”. Ownership is a relationship that a player has with other game components. This will be important in the future to determine a player’s possible actions when the game state modelling language is extended to a more general game modelling language. Ownership can be of a game component like a card or it can even be of a space on the board.
For example in the game Battlestar Galactica each player “owns” a set of cards that they can put into challenges. The cards are common between all players but each player has their own set of cards that belong to them. The concept of a “hand” of cards might then be described as “a set of cards that I own in my hand location that are visible only to me”.
Another example would be the game Twilight Imperium 3 where each player has a set of ships of their colour that belong to them. Knowing who ships belong to is an important part of the game (are those my ships defending this planet or an invading horde come to take it over).
The second concept I want to look at is the ways that players can be related to other game components. In most cases the relationship will be from one player to one component but this isn’t always the case. Where there are teams multiple players can be related to components and sometimes multiple different groups of players can be related to different components.
For example in the game Inca Empire (formerly known as Tahuantinsuyu — you can see why they changed the name!), sun cards are placed between adjacent players so that they affect both players. This means that a player will have one set of cards affecting them and the player on their left and another set of cards affecting them and the player on their right.
One way to represent this would be to have each component be related to multiple players but that might turn out to be a lot of relationships. Another way to represent this would be to use the concept of a “power set”. A power set is a mathematical term for the set of all possible sets of things. For example if we have a set of 3 players [1,2,3] then the power set of players would be all possible combinations of players or [[],[1],[2],[3],[1,2],[1,3],[2,3],[1,2,3]]. Each component could then be related to the particular set of players represented by an entry in the power set. This concept is used extensively in the software architecture modelling language called DoDAF.
Whilst players might not be a terribly interesting concept on its own the relationships of players to things in the game are important in modelling game state.
