504 is a game that creates 504 different games out of one box. The game consists of nine modules:
- Module 1: Pick-Up & Deliver
- Module 2: Race
- Module 3: Privileges
- Module 4: Military
- Module 5: Exploration
- Module 6: Roads
- Module 7: Majorities
- Module 8: Production
- Module 9: Shares
In each single game, you take three different modules from the nine available and assemble them in any order you like to create a new game. (504 = 9 * 8 * 7 = the number of distinct permutations of three items from a set of nine. The order of the three game modules is significant, and modules cannot be repeated.) For example, you can play:
- a racing game that expands through exploration with technology improving the racing or exploration (World "253").
- an 18XX-style stock game with network building for income and production sites to provide workers for the road building (World "968").
- a war game with a pick-up and deliver economy and bonus scoring from majorities ("World 417").
Each single game takes from 30 to 120 minutes to play.