Valve calls launching through portals while conserving momentum “flinging.” The technique uses the game’s portal physics to convert movement—often a fall—into speed in a different direction when the player exits the second portal.
A typical fling places one portal on a high wall and another on the floor. The player falls through the floor portal, retains the resulting velocity, and emerges from the wall portal moving outward. This lets Chell cross gaps, reach elevated platforms, or solve chambers that cannot be completed by ordinary jumping.
The term is specific to Portal’s movement vocabulary, so alternatives such as “warping” and “boosting” are misleading. Portals do transport the player between locations, but the distinctive maneuver is not instantaneous teleportation: it depends on momentum and the orientation of the portal surfaces.
Flinging is closely related to Portal’s broader design philosophy, in which the player learns physical rules and applies them creatively. Portal 2 expands the same idea with additional surfaces, gels, and testing environments, while preserving momentum-based portal puzzles as a central mechanic.