("Activating" refers to clicking without an item selected)
So, say, you're in a huge mansion, map provided. A third of people inside are traitors working together. You cannot distinguish them from non-traitors, unless they have bloodied murder weapons and are trying to kill you like handicaps. You can search dead bodies to find out what weapon they were shot with, and a piece of apparel the murderer was wearing (sans head and the decals on the chest). You have deduction and common sense, they have sneakiness and deviousity.
-Dead bodies do not disappear, and can be "activated" to inspect. If the victim was choked with a bag and the murderer wore a pirate hat, you'd see "There's a thick red line on the poor guy's neck, that emanates of rum." If The murder was a pistol to the face, and the murderer wore a helmet, you'd see "There are a few individual holes in the murderee's head, that menace with cosmic darkness."
- You can choose a trait from the start, regardless of side: (I'm aware some names don't make sense)
+ Triggerman (People can only spot you (you will be invisible when sneaking) if they place your crosshair on you directly instead of having you in their view)
+ Hollistic (You can see footsteps of different color, that relate to the players' distinctive colors)
+ Chokeslam (Attacks with improvised weapons (e.g. a bag choke, shank throatslit or door bash) will be easier)
+ Chainthief (You sprint faster and have a smaller hitbox)
+ Fell (More CQC damage)
+ Gunslinger (More pistol damage and accuracy)
+ Shneakish (Don't leave a "scent" on murder) (note: won't stop Hollistics from tracking you down)
+ Templar (Shields take more damage and can be attacked with)
- The only guns in the game are pistols because a SWAT commando detective wouldn't make sense and would be overpowered as forget
- Improvised weapons
+ Bag - A plastic bag, you can either choke enemies directly (you can be interrupted by attacking or "activating") or tie it to their necks, the latter will let you do other things while the poor guy suffocates, but will take longer and can be untied by "activating". Oh and the bag will be lost if someone retrieves it before you or unties the target.
+ Shank - A bandaged glass shard. Induces bleeding if attacked with normally, but right click with it and you slit the target's throat after a while (it has a chance of failing though). The cutthroat will be announced by a scream sound and, if you're anywhere nearby, a "You hear a bloodcurdling scream..." message.
+ You can also close doors in people's faces to stun them for a second and a half.
- Press M for map
I haven't perfectly thought this out, so suggestions are welcome.