So far a complete version of the game has never been found by investigators. Some believe that the game can be used as a means of intuitive and competitive spellcasting. Sorcerors or hapless participants fulfill the spell requirements by certain subtle strategies and tactics, draining the participants magic points and SAN points and occasionally causing fatal aneurisms as well.

It is believed that certain knowledge is required before the game can be used in this way, but the ignorant often become addicted to the game and play compulsively, occasionally accidentally casting spells through gameplay.

A Feijong tile wall is circular instead of square (curves of magic and all that). This means the tiles are slightly tapered at one end. To make it easier to see which end of the tile is narrower, and thus make the wall easier to set up, the narrower end is traditionally dipped in the menstrual blood of a freshly-dead virgin, enough to keep it visually different than the wider end. Set up is with the blood pointing inward so you get a circular wall. When packing the tiles away, the orientation on every other tile is altered to make a nice straight line. (Virgin blood is just so practical in its many uses, ain't it?)

Part of the strategy of Feijong involves not just removing tiles as in Mahjong, but turning them to manipulate the curves of the wall. If you manage to get all the Aklo tiles into a serpentine shape, for instance, you begin to wield powers related to the serpent people. Straight lines of Tcho-Tcho tiles (representing stabbing weapons) grant offensive powers. And so forth. (Rumors of time altering by setting certain Yithian tiles up on end in special patterns have never been substantiated.) Instead of Winds, there are be Outer Gods. Instead of Flowers, Servitor races. Instead of Dragons, Great Old Ones.

Feijong is not based on Mahjong - it's the other way around. Mahjong is a mundane descendant of the purity of Feijong, played with ignorance to its roots in the most ancient of history. Occasionally, a small bit of the original power seeps though in Mahjong due to the symbolic similarities, causing epileptic seizures in those sensitive to it. This has only recently begun to be noticed. Had these seizure victims instead been playing Feijong when they placed the tile that caused their seizure, then the effect would have been quite different - and so would have been the headlines.