The following is a mix of idea I got from two other MUDs/MOOs.
Since I come from Arm I can work pretty well with the theme of this game and play it as its supposed to be played. I understand the theme and setting perfectly. It's supposed to be a struggle. You have to interact RP wise a lot in order to get anywhere. Hacking and slashing will only get you killed pretty quickly. Etc.
Sadly not all the players that come have an understanding of these things. So I propose several ways to help new players and only new players to get reeled in more easily. So please bear with me.
For a month, the new player's character is protected from all adverse actions upon their characters. Robbing, getting attacked, mugged, etc. Yes this seems like a little too much. But understand that many players could be more easily reeled in if they have a month to learn the game without any of the usual ill effects everyone else has to deal with. And by everyone I mean us who have more experience. Of course there is a catch. If they perform any robbing, killing or anything of the kind that which they are protected off, the protection gets revoked and it will not get applied again. So if JoeSchmoe decides to attack a ganger from there on he is open to getting robbed, mugged, attacked, etc. So here is my next idea on this.
When JoeSchmoe is about to incur in any of the aforementioned activities a warning comes up. It should be something along these lines:
Warning! Engaging in this activity will completely revoke your newbie protection. From here on any NPC or Player can PK you. Any NPC or Player can freely rob you. Any disease can be inflicted upon your character (several other nasty things that can happen)... Do you wish to continue?
Believe it or not this can be a powerful deterrent. Specially when it is mentioned they are now 'open to PK.' Most people will think a bit more when they learn that they can now get attacked freely by anyone. Still I might be being a bit too harsh... We don't want to scare them of either. But something balanced out but that warns them that once that Newbie Protection is gone its gone and that from there on they can get robbed and attacked by anyone.