The original lexicon game rules are somewhat hard to find anymore, but anyway I'm thinking of something shorter; an abbreviated version of the game, requiring only 8 entries per player, broken down from A to Z like a telephone pad (one entry per player for a-b-c, then one for d-e-f, et cetera). Should take a little more than two weeks. Play would occur on a wiki.

Everyone writes an encyclopedia entry, one due every 2 or 3 days. Roughly 500 words minimum. Maximum: as much as you want.

1. On the first turn, each player writes either an 'A', 'B', or 'C' entry, from the point of view of an amateur, armchair historian within the setting itself (feel free to develop the personality of said scholar) . The entry should be roughly 500 words minimum, and within it you embed two citations to an entry that hasn't been written yet. At the end of the entry, you sign your name, and list the two links to other "phantom" citations that you made inside the entry -- their names exist, but their content will get filled in only on the appropriate turn.
   • No letter-group can have more entries than the number of players, either, so all citations made on the first turn have to start with non-A, B, or C letters.
   • In round 1, try to make sure you make one citation forward into the DEF grouping, so there are enough entries there for everyone. After that round, it shouldn't be a problem.
2. On the second turn, you write another entry. However:
   • Your entry must 'fill in' one of the phantom entries someone else already made.
   • You need to make THREE citations at the end. One must be a reference back to an already-written entry, and two must create unwritten entries that don't already exist. ((It's fine to also link to other phantom entries that someone else already made, but only as a 'bonus'.)) These links should be to things that in some way intersect the entry you just wrote.
3. It's an academic sin to cite only to your own work -- you can link to an entry you've written, but only if you've ALREADY back-linked to someone else's entry, so that the link to your entry is a 'bonus'. (This forces everyone to intertwingle their entries, so that everybody depends on -- and is reading -- everyone else's stuff.)
   • Again: it's no-fair writing the entry for a phantom citation that YOU created in the first place, unless there's NO other alternative.
4. On the fourth (of eight) turns, you still make three citations, but unlike previous turns, TWO must be a reference back to already-written entries, and ONE must create a new phantom citation to be written.
5. On the fifth, sixth, seventh, and eighth turns, you make two or more back-links, but unlike previous turns, ALL must be a reference to already-written entries or already-created-phantoms, because by this point you have enough phantom entries to carry through to the end.
6. Despite the fact that your peers are self-important, narrow-minded dunderheads, they are honest scholars. No matter how strained their interpretations are, their FACTS are as accurate as historical research can make them. So if you cite an entry, you have to treat its factual content as true. (Though you can argue vociferously with the interpretation and introduce new facts that shade the interpretation.)

And in case the implementation of the game isn't clear to those reading it.

First, the whole thing happens on a Wiki. Storyball.org has done a couple short story writing games that are 1st cousins to what a Lexicon game is.

Need an example?