Pocket billiards where you place gravity wells and curve the cue ball around impossible angles.
Aim and strike the cue ball, but the table is warped by gravity wells you place from a budget of three per rack. Every moving ball, not just the cue ball, bends toward a well it passes near, so almost no pot is a straight line. Read the curve, set your wells, then fire. Seven numbered balls make up each rack, and clearing them in as few shots as possible is the goal.
The 5 and the 7 sit close together near a corner pocket, but the 3 is in the way of a straight shot at them. Drop one well just beside the 3. Fired past it, the cue ball swings around the 3 instead of hitting it, clips the 5 into the corner, and runs on into the 7, which drops into the side pocket.
That one shot is worth 590 points: 125 for the 5 and 175 for the 7, 140 because the cue ball was curved before the pot, and 150 for the second ball in the same shot. A straight pot of the 5 on its own would have scored 125.
Wells pull on every moving ball, so the same well that bends your cue ball will also bend an object ball rolling past it. Place wells where they help both, and pick them up again when they start to get in the way.
The table, the cue ball and the bank shot are pool, where the whole craft is predicting angles off a cushion. Real players can bend the cue ball too: the massé and semi-massé shots use an elevated cue and heavy side spin to curve it around a blocking ball. Gravity Pool hands that curve to everyone and moves its cause from the cue to the table.
The wells obey the shape of Newton's law of universal gravitation, published in 1687: the pull weakens with the square of the distance, so halving the gap quadruples the bend. Games have used that law from the very beginning. In Spacewar!, written in 1962 by Steve Russell and colleagues for the PDP-1 at MIT, two ships duel in the gravity well of a star, and flying close to it for a gravity assist was already a common tactic.
Bending a trajectory around a mass instead of spending thrust on it is how real spacecraft navigate — a gravity assist changes a probe's course for free. Applied to a pool table it inverts the game's central skill: the angle you can see is no longer the angle the ball will take, so reading the curve replaces reading the cushion.
Gravity Pool is an original, free browser game made for PlayPendium: seven-ball racks, three gravity wells per rack, and physics that play out identically every time, so the daily rack is the same fair puzzle for every player.