As TuggyNE says, the game you are thinking of, Xorvintaal, is described in only vague details in Monster Manual V in order to leave things free and open to DMs to figure out the way they want. He does, however, seem to lament the fact that the details are quite so sparse, and thus I want to offer this: Elements of the Great Game by afroakuma. Afro is one of the best sources of D&D-lore knowledge on the internet, and his ideas here are, I think, excellent.
The following [linked above] are some of the fragmentary rules, gambits, methods, and principles sages have managed to in some way distill from decades of observing the Great Game in action. Note that the nature of Xorvintaal means that any or all of these might be misinterpretations, false assumptions based on unverified information, or local or conditional rules - the depth of Xorvintaal is simply too great to reasonably appreciate, its rules too ingrained in unspoken tradition and ritual to be accessible.