Reaction

Character reaction is a game mechanic in Fallout and Fallout 2. It reflects general attitude of an NPC towards the protagonist. The reaction can be good, neutral of bad.

Reaction is mostly changed by saying nice or mean things to the character by choosing appropriate dialogue options. For talking heads, the character's expression visibly changes.

Initial reaction (when talking to the character for the first time) is neutral unless affected by the Sex Appeal trait or NPC-specific scripting. With Sex Appeal, human characters or the opposite gender start out with Good reaction while of the same gender - with bad.

This game mechanic is much underused. Only for very few NPCs does it affect the course of the dialogue. The most prominent effect it has on gameplay is slightly affecting barter prices.