PATTERN: Rules Express Lore
PROBLEM: Games that describe what is happening in great detail, or describe things that are not happening, do not have a certain feeling. (clarify if possible?)
SOLUTION: The text, sound, visuals, and other media should communicate a less complete picture, and the rules and play should clarify that picture -- rather than the other way around. The mechanics and dynamics of the game should give the most important look at the lore.
LARGER PATTERN: To draw attention to any sort of 'form,' it should be central. I suppose in an ideal world we might say that all art 'forms' should be equal in a given work. In this case, the larger pattern could be called "Specialty Expresses Lore": whichever art form you are most confident in and most interested in should communicate the most important concepts.
Oath: Chronicles of Empire & Exile - The Chancellor's relationship to the other players and the game at large is described primarily through its rules (and rules text). There is no lore about how the Chancellor should act or what their relationship is to the other players; they simply have certain powers and restrictions, and these are described in the rulebook.
Pokemon - Shedinja, the 'Shed Pokemon', is created when Nincada evolves into Ninjask. The bug pokemon 'sheds' this ghost pokemon as it evolves into its adult form.
Through writing these examples, I realize it's not particularly clear-cut... In Oath, rules are written out as text, and some lore certain comes through in the rules text. Doesn't this count as text-based lore?