In the exploit community, a "GUI" refers to a custom menu injected into the game to gain unfair advantages. Common features found in these scripts include:
For a look at how these third-party script interfaces function and the features they offer, you can view these demonstrations: Murder Mystery 2 Gui
Outlines players or adds text above them to identify their roles (Murderer/Sheriff) or see them through walls. In the exploit community, a "GUI" refers to
A menu on the left side of the screen where players can view their weapons (knives and guns), effects, powers, and emotes. In the exploit community