I don't think there's much more that can be done than already is being done. The system seems good enough, punishments are rather severe, increasing them would be just an overkill and implementing automatic systems for RDM detection would probably be counterproductive with possible false positives all over the place (karma bans exist anyway). There's staff online almost all the time, all reports get reviewed and whatnot, seems pretty okay to me. Of course, it would be nice if you get RDMed in like the first 3-4 minutes of your traitor/detective round then you get refunded it (given that shop thingy that forces you into traitor/detective, probably wouldn't work for Vanilla, but I'm hoping they add it there as well), would really help with fighting frustration players experience when some RDMer ruins a fun round, but it's understandable if that doesn't happen.
Lower the RDM? Get regulars on. Regulars tend to stray from RDM, because they understand the rules. However, if you're looking to eliminate RDM all together, it would be virtually impossible.
As said previously by everyone, I think it's quite understandable that completely eliminating RDM is a task too difficult to perform; however, reducing it isn't. Personally, I believe the regulations and systems set in place to handle RDM are absolutely up to par.
Well, I have serveral but nothing beats... a cool head while in-game. Seriously, this will significantly lower your RDM. ^_^ Mistakes happens so keep calm and press on.
Stay aware and calm. Always calculate the chance that it wasn't them. Also if you are cool about being rdmed and just filing a report you will be golden, and if you be sincere about accidental rdm chances are the other player will be cool about it. (Note: accidental rdm means actual rdm not just shooting someone for fun and then saying "oops misclick" ) @Scott what is so dumb about this?
Understand and link the !motd or !rules while on the server, reminding players that they can find our rules that easy! The game is more enjoyable when others play it right! When someone plays TTT, they should be well aware that it is a game of rules, therefore enforcing the !motd is a big thing to help promote proper play!
How to get rid of RDM? Get rid of rules regarding RDM. Ok in all seriousness though, best way to reduce RDM is to know the rules and know what situations allow you to kill people.
There is no fine way to ever eliminate RDM. You'll always have those trolls who just join the servers purely to RDM, hot-headed players who are upset that they lost a round and choose to Revenge RDM over that round, or people who RDM either because of something happening (suspicion, accidental damage, etc). Only way to ever reduce this is to have players read the rules (both MOTD and extended rules), but even then, most new players just skip the rules, play on the servers, and then get banned due to lack of knowledge of the rules.
Add a link to the rules, or directions on how to access them built into the RDM manager/report system. So that when you go to make a report, or are reported, the rules are simply right there for new players (who may have skipped them previously) to fact check and make sure they are in the right in the situation, or simply admit that they were wrong and avoid it next time. Having the rules right there when they are needed (while reporting/being reported) would really save staff a lot of time, and get the knowledge out there to prevent further issues. I don't think too many people read over the rules when joining a server, unfortunately. A lot of them may think it doesn't apply to them and that they won't need to know them because the rules are the same as other TTT servers. Having a big, red, bold "Warning: The rules on this server are different from other TTT servers. Please read carefully" incorporated as well would probably save a lot of explaining efforts as well, and help cut down RDM done through ignorance. I know that such a thing already exists, somewhat, but it's not obvious enough, in my opinion.
I suggested this a long time ago, while I was still just a baby VIP on here, and it received a ton of positive support. I don't know why it hung in committee. A lot of times, the player base will speak up whenever they hear "live check or KOS" or "KOS the guy with the ___ skin" but not everyone listens if it's not written in giant neon letters on the MOTD.