This is a game for two players (Ann in blue and Beth in red), who are medical doctors. The circles represent towns on an island. The towns are connected by roads as shown.
The players select one (or more, depending on the rules) town as their location by clicking on the circle. Everybody on the island sees a doctor on average once a year, and people always go to the doctor closest to them (in terms of number of roads they have to travel). In case of a tie, the person would choose randomly, so each doctor could expect "half a patient". Both doctors want to have as many patients as possible. The colored parts of the towns indicate those people seeing the corresponding doctor.
You can alternately place red and blue locations. You can change the order with the "red moves" and "blue moves" buttons.
Keep in mind that in the simultaneous game version, since you cannot input both choices simultaneously, this applet is not really for playing, but for seeing the payoffs for various selections. If you want to play the simultaneous version, both players should submit their choice on paper, and then we check the payoff by inputting both moves.
Erich Prisner, 2012