Theory that there is only one True Prime Material and the others are shadows
A view held by only a small number of planewalkers, that there is One True Prime Material plane - Prime Zero - and that all the other Material planes are reflections, shadows, imitations of that plane, and not as "real" as Prime Zero. Its' detractors hold that this is merely the inability of the clueless to adjust to the infinity of the Cosmos, but the supporters of the Amber Hypothesis have equally strong arguments for its' veracity.