In the past you would get a wisp alerting you to a contract being placed on your head when you'd log in. This was removed. While I'm absolutely not sad about that, I think the assassin mechanics overall need a little bit of an overhaul. Specifically, I think timers should be looked at.
Pay off timer - target:
I don't think it's necessarily constructive to RP if a contract is placed and you can immediately pay it off. My suggestion here would be to restrict being able to pay off a contract within 1-2 RL weeks of it being placed. As it is possible to add to a contract, I would suggest the timer starts and ends with when the 1st contract is placed. This forces the person with the contract to have at least a 1-2 RL week risk of being assassinated, but not have people abuse the system by incrementally increasing the contract just to stop someone paying it off. As it is popular for the target to not be online or rarely be online while they have a contract on their head, instead of it being a flat 1-2 RL weeks, it could be a number of hours of a person being logged in with the target character. That way, they can't cheese and just not log in until they can pay it off or the contract expires. It also gives the assassin 1-2 RL weeks (and thus possibly longer depending on activity), to plan for an assassination. I think this change would encourage a lot more RP on both sides. The target having to be paranoid and surround themselves with guards or stick to safe zones or what have you and the assassin trying to learn their target's movements and strategize an attack.
Assassinate timer - assassin:
I have now seen several times where people place a contract to get their assassin to be around (I.e. online) to immediately carry out the contract for fear of it being paid off immediately. I think the above sort of helps with that fear as well, but I also believe that there should be a timer between placing a contract and carrying it out. Let's just say that the Assassin's Guild knows bureaucracy as well and needs time to process a contract request, assign the right person, yada-yada-yada. We can probably come up with a valid reason why it would take a while. I think that placing a contract while waiting for your assassin to be online so you can immediately claim it without giving the target an opportunity to put in place protections and be aware is not constructive to RP at all. So my suggestion here would be to put a timer on the moment a contract is placed and the moment it can be claimed.
With the two timers above, I genuinely feel that assassins would have more of an opportunity to plan a fun and engaging assassination while equally having a timer on when you can be assassinated after the contract is placed, provides the target an opportunity to RP coming up with protections. Maybe hiring a bodyguard or other ways to protect themselves.
I genuinely feel these timers would add a lot to RP on this server surrounding Assassin contracts.
Assassin PrC applications focus on how to make the engagement as interactive and fun as possible for the target, but for months now I've simply seen it being abused as a tool to take out settlement leaders rather than it contributing anything positive to the server. I think the timers would be a good start to improve this system and make it more fun for everyone.