The Dreaming Gods

I've been searching for a long while for a particular game.  You know, that perfect game that hits all the buttons and has something for everyone.  Alas, no one game is perfect for everyone, and convincing a group of players to try a new game system is not as easy as it sounds.  Leaving old characters to wither, learning a new game system, and difficulties in reaching a consensus about the setting are all reasons to stay within the old familiar game system, campaign, and characters.

It occurred to me recently, can I design a campaign storyline that can incorporate multiple game systems?

The Dreaming Gods will be my first attempt. The basic idea here is to use Labyrinth Lord when the characters are on the surface world, then certain places/events will be portals to other gamesystems.

Some "portals" will always cause the same results.  Anytime the PC's steal a spaceship or get kidnapped by aliens I'll probably use traveler without even trying to convert the characters...  because the thought of a wizard, a thief, and a fighter all trying to pilot a spacecraft amuses me.  Some dungeons will just be borrowed from other d20 systems and attached to the surface world.  Some will be a magical wardrobe that acts as an entrance to another world.  Despite these changes in setting the characters (and character sheets) will remain the same, and on the fly the players and I will have to agree upon the likelyhood of  their characters to accomplish a given task.

Other portals will change the characters and setting.  For example, I think that certain songs or magical effects will transport the characters into a new world.  I will randomly hand out some premade character sheets, and we'll suddenly be playing Shadow Run, or Mutant Future, Monopoly, or whatever until they figure out a way to get back home.  Very likely I will have each of them roll to see if their new character remembers that they used to be a wizard, remembers the background of their new character only, remembers both lives (and makes a sanity check?), or remembers neither but has the abilities of the new character (Jason Bourne style).

Once they return to the surface world their Labyrinth Lord characters will be able to remember what happened while they were in the other world, but it will seem hazy and dreamlike.   Instead of XP I might award +% to some skill that they used in the other game system (like computer hacking, telekinesis, or driving) so that their LL character can now use it a little.  I might also have some "artifact" return with them, some tangible proof that they were really there.  Perhaps a laser pistol, diamond ring, Klingon to English dictionary, or a bag of chips.