Now we want to predict this system forwards and we’ll use the same criterion for failure: when some particle leaves a collision 90 degrees out from where we predict. Now we want to predict where the balls go, and we’ll say that the prediction fails when a ball leaves a collision 90 degrees from where we predicted - it’s obvious that after that point we can’t usefully predict anything. When setting up a game of billiards, the first step is to rack the balls in the triangular rack, with the 1-ball at the top and the 8-ball in the center. Trickshot. Is setting up a ball position which seems almost impossible, and then pocketing the object ball. In Pool, the number of balls in a full set of pool balls varies depending on the type of the game, but a full set includes sixteen balls, each 2 1/4 inches in diameter: eight solid color balls numbered one to eight, seven balls with a color stripe numbered nine to fifteen, and a solid white ‘cue’ ball.

You can download the full game (14 megabytes), or else just look at the Read Me, which contains some interesting gameplay philosophy from the playtesters. You can download the full game (7 megabytes), or else just look at the Read Me. We don’t know one thing: there are some people standing around the table, and we don’t know where they are, so we don’t know what their gravitational fields look like. Again we know everything: the starting conditions are known completely, the box is completely understood &c &c. Stripes are numbered 9 to 15. In 8-ball, some players refer to stripes as highs. Some games require players to call all their shots, and other games make it a requirement only for the final winning shot. One day I was thinking about what kind of game I would make for Nintendo's upcoming Revolution console, and I thought it might be neat to use the controller as a paintbrush to paint pictures on the screen. Your goal is to learn to do this with the absolute minimum amount of torque needed to bind the most misaligned pin enough to distinguish it from the other one.

The red balls are worth one point each, while the yellow is worth two, the green three, the brown four, the blue five, the pink six, and the black seven. The first case is billiards, and we’ll consider a completely idealised billiard table: completely smooth, flat and rigid, completely round balls with completely known properties (so how elastic they are etc), and the same for the cushions. If you’re a fan of billiards, then you’ve probably heard of 8 pool. Bridge. Your bridge is how you position your supporting hand to hold the pool cue. Now someone makes a shot, and we either know the direction and force exactly or are allowed to measure the cue ball’s position and velocity exactly shortly after the shot. The cue is a tapered rod of polished wood or synthetic material, ranging in length from about 40 to 60 inches (100 to 150 cm).

This page contains prototypes of games that are experiments in game design. Both of these are due to Michael Berry and are mentioned in a book called ‘A Passion for Science’ which is in fact a set of collected transcripts of BBC radio programmes from sometime in the mid 1980s: I heard them on the radio originally, and they have stayed with me - I didn’t find the paper versions until quite recently. And this time we also know everything about the rest of the universe as well: we don’t need to predict it forward, we’re just given all the data about how it evolves (in fact I think that without loss of generality we can assume an empty universe outside the box, which reduces the data volume considerably). Except that there’s an electron at the edge of the universe and we don’t know where it is (apart from how far away it is), and so again we don’t know its gravitiational field. The game was played on a huge strip of land, what is billiards in this case about 1000 yards long and so was more like golf than Croquet - players took great swings at the balls in an effort to hoof them as far along the pitch as possible.