Contracts can be taken out at Assassin Guilds to kill other players in the MUD. Players can only place contracts on playerkillers or on contractable NPCs. Non-playerkillers can only have contracts placed on them if they kill or steal on Assassin's Guild grounds, and they are dealt with by NPC assassins, not PK assassins.
There are two types of contracts. Warning contracts and 'real' contracts. Warning contracts only cause a pk death and don't remove a life from the victim, you can only place a warning contract on players. Real contracts take a life.
The person who places a contract on a player can add an anonymous message to the intended victim.
Contracts are very expensive and end after a certain period of time. Warning contracts are generally cheaper. Cost may depend on age, score or guild level. Once a contract has been finished it takes some time before the person can be contracted again. research If this has been marked on a page, it's because there was something that probably isn't known, that the person who edited the page thinks could be found out. Perhaps you could figure this thing out, and be famous evermore.
NPC contracts can be finished four times after every eigth months for each different npc.