Unlike other fan-based expansions, Arkham Investigations does not attempt to add a new locale, new characters, etc. Instead, it attempts to modify the gameplay to achieve a few goals:
- Add an exciting endgame sequence when the players do well, too, not just when they fail to close gates fast enough.
- Allow for more bibliographically faithful, plot-based investigations by limiting the monster pool and including staged encounters that follow a story.
- Allow players to cooperate against monsters and location challenges (but also allow monsters to cooperate against players!).
- Provide a mechanism that allows other fan-based expansions to be easily created by other fans.