When you play TTT, you get randomly picked to be a Detective, Traitor or Innocent. To have more than 1 T buddy you need 6 people per T. So for 12 people there are 2 T's. The goal for Ts is to kill everyone but they're buddies, and for everyone else you have to find the Ts in the group before the kill you! Detectives and Traitors and buy weapons/objects to help them win the game by pushing c and using a point or whatever the server your on calls it. Innocents basicly help the Detectives by IDing bodies with DNA and calling to them.

DONT stand next to an unidentifed body no matter what you are. If you are caught next to one, you will most likely die or be KOSed ( kill on sight).
DONT walk up to an AFK and kill them NO MATTER WHAT. If someone tells you to, They are either a Traitor or should be reported to an admin or mod.
DONT make a random KOS on anyone. This will get you kicked from most servers.
DONT RDM anyone. Even if you dont kill them, Its consitered RDM if you attack another player for no reason.

So as a Traitor you have to find and kill all the Innocents and Detectives. Here are some helpful tips to keep you alive and killing.
Either hide or destroy all the bodies that you killed in dark/small places. To destroy a body either use a flare gun that is on most servers or throw it off the map.
Get on the Detectives Good side
Get SILENT Kills so you arent KOSed
Hiding places: ( you have to take the body with your Magneto Stick and right click to make it stay)
Bottom of a deep Body of water
The top of a building
Anywhere that is poision ( as long as its hard to get your good, so it can be see able)
But if you think your the Next Greatest T, Try these places
In the middle of a room
Vents
On the side of a tall building
Directly at spawn
In front of an AFK Detective.

PLEASE,
Dont be that one guy that either hides as a Traitor
This is because it is your job to hunt down everyone else so that you can do it after. If you do hide, the round may be ended or you may be slayed for delaying.

As Detective it is your role to hunt down those murding Traitors with your tools. Heres how to do it
DNA SCANNER: If you find a body or C4 with DNA on it, take the scanner and left click to track down whoever is the T. Then after he/she is dead you can make the scanner stop tracking them by right clicking it and destroying the picture.
C4 DEFUSER: When you buy this, simply click on the c4 and it will deactivate
HEALTH STATION: Place it down so everyone around you can be healthy again. To use, click E on it and gain health. Now not many people know this but you can get DNA from anyone that used it, very helpful to finding whoever your looking for.

TIPS
Dont be that one Detective that hides with a health station. Its a real ♥♥♥♥ move.
Aim for the Head for any near range shot. If the person is shooting you, only shoot at the head if you have a clear shot. Otherwise shoot for the chest.
Have everyone you can be tested and proven. If they dont, you cant kill them but can call High Suspition. That means they are being watched by everyone, everywhere they go.
Use your Voice ( or type), this means make sure everyone knows whos in control at all times and that YOU will be the Traitors worst nightmare.

You dont do a lot but Here are some tips anyways.
Kill all the Traitors: Shoot for head and chest if you cant use a trap to your advantage.
Be on the Detective's good side: He might be a ♥♥♥♥ and KOS you for no reason. If he does, tell him to 1 ♥♥♥♥ off and 2 call an admin.
Hide: Traitors cant kill what they cant see, right?