The Delusion Trigger System is the main form of player interaction in the game ChäoS;HEAd. It allows the protagonist Takumi Nishijou to view positive delusions, negative delusions, or no delusions at all at various points in the story.
At certain specific points in the game, green and red dots will appear at the top of the game window, and clicking on them will allow the player, as Taku, to view either a positive or a negative delusion respectively. Ignoring these dots will allow Taku to stay grounded in reality.
These “Delusion Triggers” encountered throughout the game which will cause the protagonist to hallucinate a:
- Humorous/perverted scene (green trigger, upper left corner)
- Dark/cynical scene (red trigger, upper right corner).
If neither trigger is chosen, the scene proceeds normally without Taku hallucinating.
Delusion Triggers have no effect on the progression of the story, but triggering certain ones are required for the B ending.
Positive delusions are often steamy and sexy in nature, and negative delusions are often gory and violent in nature. Choosing different delusions doesn’t affect the first playthrough of the game, in which only the A and AA endings are possible and the B ending cannot be reached.
However, Delusion Triggers are essential for reaching the B ending in a second or later playthrough, after reaching the A and/or AA ending(s). Which Delusion Triggers are necessary to achieve the B ending are outlined in the ChäoS;HEAd Walkthrough.
The Delusion Trigger System from ChäoS;HEAd was replaced with the Phone Trigger System in Steins;Gate and the PokeCom Trigger System in Robotics;Notes as the main form of player interaction, but the Delusion Trigger System triumphantly returns in ChäoS;Child.
The ChäoS;Child version of the Delusion Trigger System is upgraded quite a bit from the original ChäoS;HEAd version, with greatly improved graphics, making it much more obvious to the player how it works, as well as added complexity and the ability to trigger extra delusions while already having another delusion, as explained here.