Glide puzzles: when pieces slide until they stop

Puzzle world · 4 min read · Updated 29 October 2026

PaneSlide's glass does not stop where your finger stops. It glides until something stops it. That one rule is the heart of a whole family of puzzles, from ice floors in adventure games to a famous board game about robots. This guide looks at why the rule works so well and what PaneSlide adds to it.

The rule: you choose the direction, not the distance

In a normal sliding puzzle, you decide exactly where a piece goes. In a glide puzzle, you only choose a direction. The piece then moves as far as it can, until it reaches an edge or an obstacle.

That small change makes a huge difference:

• Each piece has only a few possible moves. Usually no more than one per direction.
• Stopping in the middle needs a reason. If you want a piece somewhere in open space, something has to be there to stop it.
• Other pieces become tools. Moving one piece to the right spot can create the stopper another piece needs.

So the puzzle stops being about steering and becomes about setting up stoppers in the right order.

Ice floors in video games

Many adventure and role-playing video games include ice rooms. The player character steps onto ice and slides in a straight line until they hit a rock or wall. To reach the exit, you work out a path of slides using the rocks as stoppers.

These rooms are popular with designers because they are easy to understand in seconds but can be surprisingly tricky. They are also a good introduction to the idea that you sometimes have to go the "wrong" way first to set up the right stop.

Ricochet Robots: racing to the shortest route

Ricochet Robots is a board game designed by Alex Randolph. It came out in Germany in 1999 under the name Rasende Roboter. Robots move horizontally or vertically and do not stop until they reach a wall or another robot. Each round, a target square is revealed, and all players race to find the route for the matching robot that uses the fewest moves, which may include moving other robots to act as stoppers.

Ricochet Robots shows the strategic depth of the glide rule. Finding a route is often easy. Finding the shortest route, perhaps by first moving another robot into place, is the real challenge. That is very close to PaneSlide's par.

What PaneSlide adds

PaneSlide takes the glide rule and adds a few twists of its own:

1. Pieces on rails. Each pane moves along one row or one column only. A ↔ pane slides left and right; a ↕ pane slides up and down. This keeps the choices small and readable.
2. Sticking. A gliding pane stops when it slides onto new crossing glass, so overlapping panes act as soft stoppers. This is PaneSlide's special rule, and it means a pane can stop in the middle of the board without any fixed obstacle.
3. Colour as the goal. You are not trying to reach one square. You are trying to make a picture, where every cell's colour depends on which panes overlap there.
4. Special cells that bend the rule. Ice cancels sticking, so glass glides on. Sand stops glass the moment it slides on. Stone pillars are fixed blockers. One-way glass can only go in one direction.

The glide and stick guide explains each rule in full.

Tips that work in every glide puzzle

Find the stoppers first. Before moving anything, list everything that can stop a piece: edges, walls, fixed blocks and other pieces. In PaneSlide that includes crossing glass, sand and pillars.

Ask "what will stop it there?" For every piece and every target spot, there must be something that stops it exactly there. If there is not, you need to move something into place first.

Work backwards. Think about the last move. Which piece could slide into its final place with everything else already set? Then think about the move before that.

Count the minimum. In Ricochet Robots and in PaneSlide, there is a known shortest route. In PaneSlide it is called par, and it is proven by a full search, as explained in how PaneSlide puzzles are made. Knowing the target number tells you whether a route you have found is good enough.

Beware the slide past. The most common glide mistake is expecting a piece to stop somewhere it will not. Trace the path before you move.

Why glide puzzles feel good

Glide puzzles give a particular kind of "aha". At first a target looks unreachable, because nothing would stop the piece there. Then you see that another piece can be moved to create the stopper, and the whole route falls into place. That moment, of turning another piece into a tool, is what makes the genre satisfying. PaneSlide adds colour so that each solved puzzle also leaves you with a finished window.

Sources

• Wikipedia, "Ricochet Robots" (Alex Randolph; Rasende Roboter, Germany, 1999; robots move until they reach a wall or another robot), checked 29 October 2026.