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.
Not all positive delusions can be described as “positive“ since some of them show rather negative scenarios. These are, however, labelled as such for lack of a better short descriptive name.
Appearance[]
The Delusion Trigger System in NoAH. When pressing the green button on the left side of the screen the screen gets green, while the red button on the right side makes it red.
In the original ChäoS;HEAd, the delusion triggers appear as green and red dots moving like a cardiogram at the top of the game window accompanied by the beeping sound that disappears only once either one of the dots is clicked or the delusion selection period passes.
In ChäoS;HEAd NoAH the delusion triggers take form of large green and red buttons on the sides of the screen. They are also accompanied by a static sound effect which quickly disappears regardless of the player's input.
Effect[]
While having only two buttons, the delusion trigger system offers three options - selecting the green, "positive" option, selecting the red, "negative" option, and getting through the next few lines without selecting either - the "neutral" option.
The exact effect of delusion trigger varies for every choice, but usually, as the name suggests, they make protagonist see a delusion, which is more lighthearted (and often sexual) in nature for the positive option, or grim (and often violent) for the negative option, while the neutral option keeps him paying attention to reality without getting distracted. Sometimes, picking the delusion triggers does not cause a delusion scene, but affects the way Taku reacts to his current situation, with the positive trigger making him approach things from a more relaxed and optimistic perspective, and the negative trigger making him more pessimistic and paranoid.
Choosing different delusions does not affect the first playthrough of the game, in which only the Silent Sky ending (for NoAH, or A/AA ending for the original game) is possible.
However, Delusion Triggers are essential for reaching the Crying Sky ending (known as ending B before NoAH) and the character routes (only in NoAH) in a second or later playthrough, after reaching the Silent Sky ending. Which Delusion Triggers are necessary to achieve the other endings is outlined in the ChäoS;HEAd Walkthrough.
In Other Games[]
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 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.