Random Death Match, also called "RDM" is when a player kills another play without a valid role-play reason. An example of "RDM" would be player A killing player B because of their name, an example of something that is not "RDM" is player A raiding player B and killing player A in his base.

New Life Rule, also known as "NLR" is a rule which states that you must forget everything in your previous roleplay on death.It also states that you must not return to the district you were previously in on death for 3 minutes
An example of someone breaking NLR would be player A being killed by player B during a raid, and player A returning to the raid immediately, breaking NLR. An example of NOT breaking nlr is a S.W.A.T dying during a nuke raid and returning back immediately.

Metagaming is where something to do with Roleplay stated in Out Of Character chat. An example would be player A stating they are getting raided on OOC to player B and taking that into an advantage.

I would suggest for the player to make an admin request about Random Death Match, teleport player X and teleport to player Y to check if he is busy, then I would telepeort player Y asking why did player Y kill player X, if the response would be something like, "He mugged my buddy when I had a weapon out." Then I would ask player X privately if this is true, if he said no, then I would ask his side of the story, if player Y denied the story then I would ask player X for proof, if there was none I would end the sit and tell him to get some proof the next time and I would warn him, if player X had proof then I would warn player Y of RDM and tell him not to lie to staff again and teleport them both back.

I would teleport to Player X and check whether they were busy or not, then teleport them to a roof somewhere. I would then bring Player Y to the roof and ask if Player X had any proof. If Player X had valid proof/if Player Y admitted to breaking NLR, I would tellPlayer Y to read the rules again, warn them, then teleport them both back. If Player X had invalid/no proof and Player Y denied breaking NLR/had counter-proof, I would teleport Player Y back and tell Player X to take screenshots/record next time. I would close the admin request by teleporting player X back to where he was and tell him to make another admin request if he does this again and records him.

I would tell player x not to metagame as OOC is out of character and instead to put it in /advert next time.