This represents a reenactment of an old game system, with new text. I mentioned that I was considering something like this a while ago. The original is from [1], but I didn't go back and look at it until I'd almost finished mine (that was when I decided to add the Library and the fungibility clause, but I don't think I stole much else). I'm not actually sure how much they'll be used, but I've managed to squeeze it down to a single rule so the ruleset addition isn't huge even if they aren't used much. Thoughts and comments are welcome!
[1] https://mailman.agoranomic.org/cgi-bin/mailman/private/agora-official/2011-June/008818.html -Aris --- Title: Promises Adoption index: 2.0 Author: Aris Co-authors: Enact a new power 2.2 rule, entitled "Promises", with the following text: Promises are a class of assets, tracked by the Notary. Their essential attributes are their title, text, and creator. A person CAN, by announcement, create a promise, specifying its text and becoming its creator. A promise's owner is referred to as its bearer. Promises with the same title, text, creator, and bearer are fungible. A promise's bearer CAN, by announcement, cash the promise, provided that any conditions for cashing it specified by its text are unambiguously met and provided that e recites the promise's essential attributes in the same message. When e does so, e acts on the creator of the promise's behalf, causing em to act as if e published the promise's text. By creating a promise, a person consents to it being carried out. In a promise's text, "the bearer" (or the like) refers to the promise's bearer, and "this promise" (or the like) refers to the promise. The text of the promise can refer to the context of the message in which it is cashed, but the context of the message does not otherwise change the meaning of the promise. The Library is an entity and CAN own promises. Any player CAN take a promise from the Library by announcement, provided e cashes the promise in the same message. Amend Rule 2608, "The Notary", by changing the numbered list to read as follows: 1. every pledge, along with its title, creator, time window, time of creation, and time of expiry; 2. every contract, with its title, full provisions, and parties; and 3. every promise, along with its title, text, creator, and bearer.