Sorry to kill the romance, but there is nothing inherently magical or spiritual about “abbey beers”—those beers that imitate or get inspiration from the Trappist archetypes. For that matter, there’s nothing inherently special about Trappist beers either, beyond the fact that they’re brewed within the walls of real working abbeys.
Once we blow away the mists of mystique and marketing, the rest is recipe. Then we can really mess with things—just as brewers in Belgium have been doing for years. They have done so beyond the mainstream, which lately threatens to change course and follow the oddities in the international flood of variety.
If there are few rules, there are at least traditions. Thus these examples are based on the structure we know—singles, dubbels, tripels, and … strong dark ales. (Cool Belgophiles don’t use the word “quadrupel” since the Belgians don’t—not counting the few Belgian brewers who started doing it recently for the U.S. market.)