In chess, algebraic notation refers to a representation of the game pieces on a coordinate grid. This allows any scenario in the game to be visualized and discussed without having to arrive at it in the course of normal play. Representations of ideal cities offer an analogous system of notation for architects and planners. Free from the contingencies of real city making, formal elements and arrangements of urban space can be examined in abstraction.
Borrowing from chess, both as a game and a field of study, this working model of an ideal city can be used to test and record iterations of related arrangements in both physical and notational form.
Unlike chess, cities do not have universal rules, but they do have traditions and conventions. They are composed of sets of related elements like public buildings, residential fabric, and urban spaces. This model defines sets by formal types: tectonic cages (gold), stereotomic architectural solids (wood), and subtly irregular orbs (clay). To these elements, found objects can be added to create novel arrangements.
Since there are no rules, the dimensions of the gridded surface are arbitrary. It is still possible to play the game, either by inventing provisional rules or by beginning with an already-notated starting position and rearranging the elements as a critique.