Portal 2: Puzzle Solving Mindset and Gel Mechanics
How to approach Portal 2's logic puzzles, plus a breakdown of every gel type and how to use them.
The Core Loop: Observe, Hypothesize, Test
Every Portal puzzle is solvable with the tools in the room. If you're stuck, the answer is always: look at every surface, every cube, every button, every portal surface (white panels). The game never requires pixel-perfect execution — if a solution feels impossible, you're missing a step.
The Gels
Chapter 6 onward introduces three gel types, each with distinct properties:
- Repulsion Gel (blue): Bounces anything that touches it. Used to cross large horizontal gaps or reach high platforms.
- Propulsion Gel (orange): Massively increases running speed when traversed. Used to build momentum for jumps.
- Conversion Gel (white): Makes any surface portal-able, including normally unpaintable walls, floors, and ceilings.
Gel Physics Key Points
Gels flow and splash. You can redirect a gel flow through a portal — shooting it into a wall portal and out of a floor portal coats the floor. You can also wash gel away by directing a water stream over it (water appears in certain chambers).
Funnels (Excursion Funnels)
The blue beam Excursion Funnel moves objects and players in one direction. You can reverse its direction by shooting a portal on the opposite end. You can ride a funnel while airborne and exit by moving perpendicular to the flow.
Light Bridges
Light Bridges are flat surfaces of light that can be redirected through portals. A bridge entering one portal exits from the other — at any angle. The key insight: a vertical bridge (portaled through a wall) becomes a floor. This is used to route light bridges around corners and through multi-room sequences.