My idea: Add smells to the game. How it can/would serve a purpose: Smells could be smelled (duh) by players, and either given a visual or audio notification of the smell the are perceiving, or have the cause of the smell highlighted to recognize it. Smells would tell players if other players and SCPs have been in the area and what to expect, so they would add some degree of investigation and planning. However, smells provide two major threats. Smells could cause physical responses and side-effects from players such as nausea (shaky vision), headaches (audio impairment), vomiting (slower movement and the smell of vomit), coughing and sneezing (noise). Smells can also affect an NPC or an SCP's behavior: they can be attracted or repulsed by them, be compelled to investigate them, comment on them if capable of speech, or enter a rage state in a manner similar to sharks (I mean, it's a myth, but it conveys the idea). The ideas I had are: -blood: pools of blood, fresh corpses, wounds, blood tracks (tracks you leave if you stepped on, you guessed it, blood) attract SCPs and could enrage SCPs such as 058 or 082, also triggering physical responses in players; -fire: gunfights, flamethrowers, recently activated tesla gates, burnt stuff such as electronics or flesh leave a lingering smell, but floating particles may have players cough or sneeze; -corpses: old corpses would attract or repel SCPs and NPCs, also triggering physical responses in players and NPCs; -sweat: after long, physical exercise (for instance, running) or in warm areas, players will begin sweating and may attract predatory SCPs such as 939 or 940. There could be many more ideas for smells, other than these. Why I think it should be done: It could add some realism and interesting strategy components and threats to players. How it can be done: I think that it could be done in a way similar to Half-Life: things that smell emit a ''noise'' that would be technically considered a sound, but that triggers the above responses from AI and players. This video has more info on how Half-Life implements smells: https://www.youtube.com/watch?v=1tvz0WVaQGg&t=144s Relevant images/concepts: N/A.