How to add Kolyarut clause to a contract?

[Jon_Dahl]

A dying nobleman asks the PCs to sign a contract and swear an oath to him on his dying bed. If the contract is broken, a Kolyarut will hunt the PCs down. Game mechanically, how to do this?

Clerics are not available. The noble can hire maximum 11th-level arcane casters. Psions are also a possibility. I'd rather not have any over-the-top solution, because I try have a low-magic Greyhawk campaign (with occasional slips).

The contract itself is fair, even though challenging for the PCs.

[Asheram]

A dying nobleman asks the PCs to sign a contract and swear an oath to him on his dying bed. If the contract is broken, a Kolyarut will hunt the PCs down. Game mechanically, how to do this?

Clerics are not available. The noble can hire maximum 11th-level arcane casters. Psions are also a possibility. I'd rather not have any over-the-top solution, because I try have a low-magic Greyhawk campaign (with occasional slips).

The contract itself is fair, even though challenging for the PCs.

Well, there is a contract in Complete Arcane which strikes the breaker of the contract Deaf, Blind and Mute. It's not exactly what you are looking for but might be considered.
Contract of Nepthas, it's called.

[Crake]

iirc Kolyaruts hunt down contract breakers on their own. It doesn't need to be in the contract at all, if the players break the contract, a Kolyarut was watching (or learns of it in passing), and is disappointed, and vows to hunt the players down and punish them.

[Jon_Dahl]

Well, there is a contract in Complete Arcane which strikes the breaker of the contract Deaf, Blind and Mute. It's not exactly what you are looking for but might be considered.
Contract of Nepthas, it's called.

Thank you Sir, that was brilliant! I'm going to use that, thankyothankyou! Well... My question is kind of moot now, but I'd still like to hear an answer.

[Thanatosia]

As Crake said, I think Kolyarut's take up enforcement on their own indecipherable initiative. If there was any way to reliably 'ensure' kolyarut enforcement, why wouldn't everyone include it automatically in any significant dealing?

I think there would be sweeping ramifications to the campaign setting if there were ways to guarantee Inevitable involvements... so adding something like that would be very much up to a DM wanting to set his game in such a setting. If you are the DM, then of course, it's all up to you.

[Craft (Cheese)]

Well, the problem with having the Kolyarut decide to hunt the PCs down on its own initiative is that it sounds like the OP wants the players to know the consequences for breaking the contract before they actually go and break it.

It strains credibility to have a Kolyarut show up and say "Hey guys, I've just decided that I'm keeping an eye on you for no reason in particular: Break this contract and I'll kill you." So we need a way for the nobleman to guarantee the Kolyarut's involvement somehow, or give the Kolyarut a good reason to be invested in whatever the PCs are obligated to do.

[Yora]

There are so many contracts broken all the time, yet there aren't millions of kolyaruts swarming over the world punishing people every day. You'd have to have a contract of cosmic significance to get their attention.

However, I think a scroll of greater planar binding should do the job. Since the kolyarut is asked to do something he wants to do anyway, the payment would probably be rather small. And if the PCs do their job, then he won't have to take any action at all and just keep the payment.

[Slipperychicken]

IIRC, Mechanus does this kind of thing independently. They send Inevitables after only the most important and heinous offenders, but Inevitables will also deal with "minor" offenders encountered in their path.

You could have a Craft Contingent Spell which activates a pre-written Sending (or other notification spell) to whichever enforcement agents are relevant to the contract. The message indicates that the PCs have violated the contract's terms and are subject to legal action and penalties associated with violation.

[Thanatosia]

There are so many contracts broken all the time, yet there aren't millions of kolyaruts swarming over the world punishing people every day. You'd have to have a contract of cosmic significance to get their attention.
I don't think it does have to be cosmicly significant to get their attention. That's the thing with inevitables, they have their own indecipherable method of determaning what contracts to enforce that no non-inevitable could ever understand. I think the more 'significant' the contract is the higher chance of inevitable involvement, but the odds never reach 0 or 100% no matter how big or small a deal it is.

As for a way to 'tip the players off' that this particular contract WILL invoke an inevitable response, why focus on building it into the contract? Maybe let an oracle or diviner drop them a hint to the future in some way.

[Big Fau]

Have the Kolyarut witness the contract being formed via Planar Binding. Once observed, Mechanus will have a record of it and then send wave after wave of Terminators Kolyaruts after the people who break it.