Rules, solving tips and practice boards

Inkwell Loopy River: how to play and how to solve it

Loopy River is a daily logic puzzle from Inkwell Games. You draw one river that winds through every open square and meets itself at the end. Here are the rules, the moves that get you started, and three free boards to draw on.

Try a board

Drag from square to square to lay river, or tap two neighboring squares. Drag back over river to lift it. On a keyboard, hold Shift and use the arrow keys.

The rules of Loopy River

The river moves between squares that share a side. Your finished river has to follow these rules:

  • It is one single loop that ends where it started.
  • It flows through every open square, once each.
  • It never branches and never crosses itself.
  • It can't pass through a wall or into a blocked square.

Put together, every open square ends up with exactly two pieces of river: one coming in and one going out.

How to solve Loopy River

The whole puzzle runs on that last idea. A square needs two ways out, so whenever a square has only two ways left, the river must use both. In the diagrams below, blue is river already drawn, gold is the river each step adds, and thick black lines are walls.

1. Start in the corners

A corner square has just two neighbors. The river has to come in through one and leave through the other, so you can draw both pieces right away. Do this for every corner before anything else.

2. Blocked squares make more corners

A blocked square stops the river the same way the board's edge does. A square squeezed between a blocked square and the edge has only two open neighbors left, so it works just like a corner.

3. Follow the only way on

When a square already has one piece of river and only one other way out, the river goes that way. Walls cut off options just like blocked squares do, so check both sides of every wall.

4. Close off finished squares

A square with two pieces of river is done. Its other sides can't carry river, so mark them. Those marks often leave a neighbor with only two ways out, and the chain keeps going.

5. Never close the loop early

The river is one loop through every square, so it can only close at the very end. If joining two ends of a stretch would make a small loop while other squares are still waiting, that join is ruled out.

A trick from the checkerboard

Color the grid like a checkerboard in your head. Every step the river takes moves it from a light square to a dark one or back again, so a loop always uses the same number of each. That one fact is behind some of the cleverest Loopy River moves, especially in tight corners. Inkwell's own blog has a guest guide to the checkerboard idea that walks through it on a real board.

For the other Inkwell puzzles, see our guides to Stars and Fields, or the guide to all four Inkwell puzzles.

Want more boards like this?

We don't publish a daily Loopy River puzzle, at least not yet. If you'd play one, let us know, because that's how we'll decide:

In the meantime, Inkwell's Stars has a free home here. Stars is Star Battle, and we publish new boards every day, with an open archive and a step-by-step solution for every Inkwell Stars board.

TryHard Puzzles isn't affiliated with Inkwell Games. Loopy River is their game, and the practice boards on this page are our own.

Loopy River FAQ

What is Inkwell Loopy River?

Loopy River is a daily logic puzzle from Inkwell Games. You draw one river that loops through every open square of the grid and joins back up with itself.

What are the rules of Loopy River?

The river is a single closed loop. It passes through every open square once, never branches and never crosses itself. It moves between squares that share a side, and it can't cross a wall or enter a blocked square.

Where do I start a Loopy River puzzle?

In the corners. A corner square has only two neighbors, so the river has to use both of them. Walls and blocked squares create more squares like that, and each one hands you two pieces of river for free.

Do you have to guess in Loopy River?

A well-made board has one answer, so every piece of river can be reasoned out. The practice boards on this page each have exactly one loop, and each one can be solved without guessing.

Can I play more Loopy River puzzles here?

For now we have the three practice boards on this page. We don't publish a daily Loopy River board yet. If you would play one, tap the button on this page so we know.

Is TryHard Puzzles affiliated with Inkwell Games?

No. We are an independent puzzle site and are not affiliated with Inkwell Games. Loopy River is their game, and the practice boards here are our own.

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