|Attention, Adept of the LEXICANUM!|
The Plan was an original concept of how the world should be, according to the Old Ones. The world was modified to fit that plan by shifting the tectonic plates, moving the planet closer to the sun to warm it, creating/nurturing some races (Lizardmen, High Elves, Dwarfs, Men, Halflings, Giants, and Ogres), and having the Lizardmen wage war against races that were not part of the Plan.
The Old Ones spoke directly only to the Slann, who then delegated to the rest of the Lizardman society to carry out those wishes.
However, the Great Catastrophe sealed off the Old Ones from this world.
Those Slann who had stood in the presence of the Old Ones are no longer alive, and so much time has passed that the Old Ones are viewed as long-distant gods by the Lizardmen. There exists many relics from the Old Ones including sacred plaques that the Slann contemplate to try and carry out the Old One's original Great Plan. However with the rise of Chaos, many believe the Great Plan to be impossible to complete.
The Great Plan can provide a very mysterious and seemingly contradictory set of principles for a race that worships its tenets and believes so firmly in divination. It has been recorded that Lizardmen armies will put off destroying an enemy army that has no chance of survival because of chance signs in the nearby sand that hint of prophecies of the Great Plan. The initial contact with the High Elves resulted in attack because it was deemed not part of the Great Plan, yet the Lizardmen have actively helped and abided their presence in other areas.
Slann Mage-Priests will meditate for days and up to centuries trying to hear echoes of the Old Ones and understand the Great Plan.