Sokoban with Portals

Sokoban with Portals extends the classic Sokoban formula by adding teleportation portals to the warehouse floor. When the player or a crate enters a portal, they are instantly transported to the linked portal elsewhere on the level. This mechanic opens up entirely new puzzle possibilities — crates can be teleported across the map, walls become less of an obstacle, and the spatial reasoning required leaps to a new level. Portals can make previously impossible configurations solvable and create mind-bending puzzles where the shortest path goes through multiple dimensions.

Rules

1. All standard Sokoban rules apply: move in four directions, push one crate at a time, place all crates on targets.
2. Portals appear as marked tiles on the grid, always in linked pairs (same color or symbol).
3. When the player walks onto a portal, they are teleported to the matching portal and appear on the other side.
4. When a crate is pushed onto a portal, it is teleported to the matching portal and exits on the other side (maintaining the push direction).
5. If the exit side of a portal is blocked (by a wall, crate, or the player), the teleportation does not occur — the crate or player stays in place (variant rules may differ).
6. Some variants include one-way portals that only work in one direction.

Strategies

• Map the Portal Network: Before moving, identify all portal pairs and mentally map where each one leads. Think of linked portals as shortcuts through the level.
• Plan Crate Teleportation: The most powerful use of portals is teleporting crates to otherwise unreachable areas. Consider which crates need to pass through which portals and in what order.
• Directional Awareness: A crate exiting a portal continues in the direction it was pushed. Plan the push direction before entering the portal to ensure the crate lands where you want it.
• Portal Blocking: A crate sitting on a portal blocks it for both the player and other crates. This can be intentional (to walk past without teleporting) or problematic (blocking a needed transit route).
• Think in Loops: Portals can create circular paths. A crate can be pushed through a portal, then around the level, and through the same portal again from a different angle.
• Standard Sokoban Principles Still Apply: Avoid dead corners, preserve maneuverability, and work on the hardest targets first.

Sokoban with Portals emerged naturally from the Sokoban community's tradition of creating rule variants. The concept of adding teleportation to push puzzles dates back to at least the early 2000s, when online Sokoban communities began experimenting with level editors that supported custom tiles and mechanics.

The portal mechanic in puzzle games was significantly boosted by Valve's "Portal" (2007), which introduced millions of players to the concept of spatial puzzles involving teleportation. While Portal is a first-person 3D game with different mechanics, its cultural impact encouraged puzzle designers across all genres to explore teleportation mechanics. Several Sokoban variant games incorporated portals in the years following Portal's release.

Notable implementations include levels in David W. Skinner's extended Sokoban collections, community-created levels on sokoban.info, and standalone games like "Portal Push" and "Warp Push" on mobile platforms. The mechanic has also appeared in hybrid puzzle-platformers like "Cosmic Express" and "Recursed," where teleportation and push mechanics combine with other puzzle elements.

The addition of portals to Sokoban is particularly interesting from a computational perspective. Standard Sokoban is already PSPACE-complete, and adding teleportation does not reduce this complexity — if anything, it increases the search space that solvers must explore. Human solvers, however, often find portal levels more approachable because the portals provide intuitive shortcuts that reduce the number of moves needed, even as they increase the conceptual complexity.