I'm going to have to refer you to Eliezer's TDT document for that. (If you're OK with starting in medias res, the first mention of this is on pages 22-23, though there it's just specialized to Newcomb's Dilemmas; see pages 50-52 for an example of the limits of this hack. Elsewhere he's argued for the more general nature of the hack.)
Ok thanks.
I'm coming to realize just how much of this stuff derives from Eliezer's insistance on reflective consistency of a decision theory. Given any decision theory, Eliezer will find an Omega to overthrow it.
But doesn't a diagonal argument show that no decision theory can be reflectively consistent over all test data presented by a malicious Omega? Just as there is no enumeration of the reals, isn't there a game which can make any specified rational agent regret its rationality? Omega holds all the cards. He can always make you regret your choice of decision theory.
A monthly thread for posting rationality-related quotes you've seen recently (or had stored in your quotesfile for ages).