So last week I talked a bit about how the content of the Deeps was kinda a guideline and that it wouldn't mess up much if you changed it to suit your taste or campaign. One thing discuss was the idea that maybe there are more than five Deeps in your game....
Five seems to be a somewhat arbitrary number. We know that the Afterworld is coming out of a Fall and hasn't been utterly buried and locked in magical stasis in favor of a new society of intelligent sea otters.
Side note: Intelligent sea otters would make for a badass coastal kingdom in just about any setting.So from that we can assume that there have not been exactly five Falls prior. It's possible that only certain actions of the gods cause the creation of a Deep. Or maybe there's something special about the Deeps that is unrelated to the Fall itself. Who knows? I don't ... except where my own personal version of the game goes.
So armed with that information why not expand on the idea of the deeps? Why not have six deeps? Or sixteen? The world is like an onion and the more layers you peel away the more you uncover, at least until you finally find the heart. It takes 20 total Advancements to "max out" and reach Tier 6. Optional rules for play beyond Tier 6 do exist and in a game about Gods that could certainly be a viable option, at least for a bit. A GM could set up twenty unique Deeps, and instead of the usual Advancement via Experience hand out Advancement each time the group moves to a new, deeper, tier. This could mean playing for a few sessions without advancement while the PCs try to escape the current tier and move to the next, but if your group is looking for an epic campaign in both scope and length, this is one way to do it.
Granted, added fifteen new deeps is a LOT of work for the GM, and the gimmick might wear out its welcome before the campaign could come to a close, but it's certainly possible. It's equally reasonable to just add a couple of Deeps. Heck you could just take a narrative "out" and say that after many weeks of exploration the groups have reached the Xth deep, skipping right over a bunch of other deeps. This lets you add to the setting, perhaps for a future game, but not add to the immediate work or the length of the campaign.
Why add more Deeps? Well, I suppose there's two big reasons: to add length to the campaign, and to expand the scope of the setting. I've clearly demonstrated the former, but what about the latter? Well the whole idea of Gods of the Fall is somewhat cyclical. Gods rise, rule, Fall, and are replaced by new gods who repeat the cycle, rising, ruling and in time Falling once more.
If we choose to assign direct correlation to the Falls and the Deeps this means that there have been five Falls, and five prior wolds locked away beneath the earth. If you do subscribe to this view adding more Deeps means adding more Falls. This implies the world is older, it indicates that there have been far more gods who have perished, failing to learn from the prior Falls and failing to break the cycle in some way. It means that the characters stand at the cusp of a new cycle, not one that is five incarnations long, but possibly far, far more. Perhaps the Anhilation Seed still rests in the Fifth Deep, and perhaps it is not a unique catalyst for the Falls but merely the most recent. There could be dozens or hundreds of Deeps beyond the Fifth. The character may never set foot in these long ago crypts for dead worlds, but knowing that they are there will add weight to their struggle for survival.