Aequor

What is Aequor

Aequor is a stepwell seen from the side: basins at different heights, cut into stone, with two overflow shafts at the ends. Lotus seeds are carved into the walls at the height the priests set, and a seed opens when the water stands exactly at its mark — its own square wet, the square directly above it dry. Not a course over, not a course under.

The rule is one sentence: every drop rolls to the deepest place it can reach, and it never climbs. That single sentence produces everything else — basins that fill from the bottom, water that levels itself across a floor, and a basin that spills into its neighbour the moment it reaches the lip. What makes it a puzzle rather than a toy is that when a chamber opens, it has already rained. Some seeds start under water, and pouring only ever raises a level. Those can be saved one way only: by taking stone away.

How to play

1. Tap a column to empty a jar into it. A jar is four measures, they fall one at a time, and each one settles at the deepest cell it can reach by falling and by sliding along a surface. Water that reaches an end shaft drops out of the well and is gone, so an overflow is not a small mistake.
2. The chisel takes one course off the top of a wall or off the floor of a basin. Lower a wall and the water runs into the next basin; lower a floor and the basin deepens, so its surface drops. That is the only way down: pouring raises, chiselling lowers.
3. A seed opens when its square holds water and the square above it does not. Open every seed in the chamber at the same instant and the stair below unlocks. A drowned seed shows a red cross, and it is not lost — drain the basin and it opens.
4. You get exactly the jars and chisels that the shortest solution needs, and not one more. That is not a figure of speech: before a chamber is handed to you the game searches every move you could make, finds the shortest way through, and hands you that budget. Undo (Z) and restart (R) cost nothing but the clock. Points come from finishing a chamber, from anything you did not spend, and from speed.

Strategies that work

• Read the dashed line, not the seed. The mark runs across the whole basin from wall to wall, because what has to be right is the level of that basin — not something about that one square.
• Count in cells, not in jars. A basin three squares wide takes three measures per course, and a jar is four. That mismatch is the whole arithmetic of the game: the fourth measure has to go somewhere, and deciding where is usually the puzzle.
• When a seed starts drowned, work out how much has to leave before you pour anything anywhere. Lowering a wall sends the excess into the basin next door — which may be exactly what that basin needed, or may push its own seed under.
• Lowering a basin's floor drops its surface by one course without moving a drop out of the well. When you are one course too high and the neighbour is already right, that is the move.
• Pouring into a wall column is legal and sometimes correct: the measures land on the wall top and roll off to the lower side. It is how you feed a basin whose own mouth is blocked by water.

A little history

A stepwell is a well you walk down into. From about the seventh century, across Gujarat and Rajasthan, whole villages cut staircases into the ground until they met the water table — Chand Baori at Abhaneri has some three thousand five hundred steps down thirteen storeys. They were built for a climate that delivers a year of rain in a few weeks: the point was never to lift water out but to hold it, and to keep a level you could reach in every month of the year. That is the shape this game borrows. The physics is the older half of it — that water finds its own level is Archimedes and Stevin and every mason who ever set a course of stone by eye. What is new here is only the cruelty of the arithmetic: a well that is already too full, a fixed number of jars, and one chisel.

Frequently asked questions