Research-backed game lineage
Portal is included in the Series Atlas after independent recognition and an authoritative game-by-game roster audit. Editions, simple ports, DLC, bundles, canceled projects, and cameo-only appearances are excluded.
Release chronology
Ordered by researched series position, then original release date. Ports, DLC, and duplicate editions are intentionally excluded.
2 games in this lineage
Waking up in a seemingly empty laboratory, the player is made to complete various physics-based puzzle challenges through numerous test chambers in order to test out the new Aperture Science Handheld Portal Device, without an explanation as to how, why or by whom.
Sequel to the acclaimed Portal (2007), Portal 2 pits the protagonist of the original game, Chell, and her new robot friend, Wheatley, against more puzzles conceived by GLaDOS, an A.I. with the sole purpose of testing the Portal Gun's mechanics and taking revenge on Chell for the events of Portal. As a result of several interactions and revelations, Chell once again pushes to escape Aperture Science Labs.
No games use that relationship label.
Sources and method
Membership is researched from external official and independent sources. Mainline games, direct spin-offs, remakes, remasters, and standalone expansions are included; DLC, simple ports, duplicate editions, compilation-only duplicates, rumors, cancellations, and cameo-only crossovers are excluded.
IGDB maintains a distinct collection record for Portal and supplies the authoritative roster used for membership verification.
The independent catalog recognizes Portal as a multi-game franchise and supports its inclusion in this major-series research sweep.