>The party is stuck on a planet starting at a high level and

>>50645281
>Meaning they lose levels the more they stay there.
Your players are going to punch you in the face.

>>50645281
While it is a fun gimmick, in terms of rules and mechanics yout players would just be getting access to fewer and fewer abilities, and losing their best ones all the time.
Which might be more frustrating than fun.

>>50645281
The planet is full of memory loss drugs; in the air, in the water, in the soil. You gradually forget all your experiences. It is a planet of Lotus Eaters, stuck there because they forgot they could leave.

The BBEG is immune to the drugs. He was banished to the planet for some horrible crime, but became immune to its effect. BBEG wants to get off the planet, and propagate the drugs to make the galaxy forget his original crime.

The PCs are the only ones that can... wait, what were they doing here again? Oh, right, a sandbox campaign...

>>50645281
Depending on the system and how quickly the characters change level would determine how long they have to beat the bad guy before the fight is unwinnable.

BBEG is losing fights on purpose, which causes him to gain levels.

>>50645281
Sounds awful. Not very fun.

>>50645527
>Ok.jpg

>/tg/, my group kicked me out, what do?

don't actually play through losing levels. That is unfun. see >>50645337

>>50645343
Building off that...

>session 0
Have the players set up character concepts and build them for max level. The session is a fight against a BBEG who wants to corrupt all of reality, or something. If the BBEG wins, he mocks that the PCs "might be better next time". If he loses, "I was unprepared." Either way, some sort of spell goes off, fade to black.

>Session 1
Any PCs that survived the fight of session 0 are remade as lvl 1 adventurers. Any of those that died can draft up a lvl 1 that still fits the archetype of their dead Epic Heroes. The rules for their characters is that none of their loved ones, especially those that raised them, are allowed to be directly involved in the session 1 adventure. After killing rats, or something, the PCs feel like they are waking from a dream, and level up.

>Throughout the campaign
Every time the PCs would encounter one of their loved ones, the loved ones are missing. Their homes are filled with an arcane mark, reminiscent of the BBEG from session 0.

>The setting
History of this world is defined by Heroic Ages, where a band of heroes unites to drive the forces of darkness back and herald in a new age of civilization. Eventually the heroes fade away, and the forces of darkness reclaim the land until new heroes arise. No one knows how long this has been going on for.

The spell at the end of session 0 is one of reincarnation, memory loss, stalling old age, and wanderlust, but it binds the fates those effected. This way it isn't JUST a reincarnated heroes plot; they WERE the heroes. Every single time. http://www.utpjournals.press/doi/pdf/10.3138/jrpc.23.2.236

Leveling in reverse would probably feel pretty awfull in a few ways, but I can imagine how It could be done.

Firstly reverse the experience curve. In other words going down from level 20 to level 19 will happen very fast. going from 19 to 18 will be slower. etc etc etc. Eventually they hit a point where down leveling will be slow enough that they regain some consistency

>>50645343 is a good idea. work in a way for the PCs to regain fragments of their lost power, at least on a temporary basis. The PCs stumbling into the last fight with the bbeg at level two or something, and finding some way to miraculously power up for the final confrontation seems like a cool climactic moment. Just try not to have power only go down. Maybe have them gain xp as normal, but put them all under a constant xp drain so that they can combat it directly by gaining more xp in various ways.

In other words, Don't have xp go down and only down, have levels be fairly fluid, but with a distinct downward trend. Might be best if before the game you have the players roll level one characters, then save one sheet for each level, so they can go from one to the other easily. Things are slowly getting worse and worse, but give them awesome moments where they for a fleeting moment become the bad asses they once where.