5e Skull & Shackles AP
5e Jade Regent AP
5e Dwimmermount Sandbox/megadungeon. roll best 3 of 4d6 in order for starting PC, allow hiring of PC-class retainers (max retainers 2+CHA bonus) who use the same stat gen system, but no feats or multiclassing unless they become full PCs. Everyone starts at 1st; PCs roll for starting gold. Choose or roll for Background. Gritty rest variant.
A recovered Nazi Cthulutech teleportation gate device, the Reise-Tor-Gerät, allows instant travel from home base in London to other TCs whose coordinates can be determined. The first decoded TC lies beneath Schloss Heiselburg - in January 1942, Allied agents uncover a Nazi Cthulutech Megadungeon in the German Alps. Who knows what dark secrets lie within, or what plans are afoot.
Meanwhile there are rumours that the Reise-Tor-Gerät may be able to access alternate worlds...
PC-PC-NPC relationship maps? "X wants Y from Z"?
Grey Box Forgotten Realms sandbox - 5e or Labyrinth Lord +AEC? With WoTC 5e APs? Dyson's Delves & PF Battlemats for lots of dungeons?
'Metal Labyrinth' LL/Mutant Future sci-fantasy mashup w alternate classes set in Current Year.
Game of Thrones with divergent timeline. After the death of Robert Baratheon, the King's Hand Eddard Stark arrests Queen Cersei on charges of high treason. The young Princes Joffrey & Tommen are also imprisoned, but Princess Myrcella is smuggled to safety by Ser Jamie. The Lannisters rise in revolt. While Stannis moves from Dragonstone to take the throne, his brother Renly also revolts, claiming the kingship, and is supported by the Tyrells. In the north the Starks & Tullys mobilise against the Lannisters. The Vale stays neutral. In the East a Dragon Queen rises, a Dothraki army at her command. And in the North the White Walkers are on the move...
ASoiAF rules, or could use Pathfinder Beginner Box?
4e FR Undermountain with Grey Box FR + The Savage Frontier. Ancestors of the 'Loudwater' campaign PCs?
LL or 5e Stonehell with Black Pudding classes. Wilderlands near CSIO?
Savage Rifts or just Savage Worlds, with Venger Satanis stuff - Isle of Purple Haunted Putrescence
Savage Deadlands in Leone's Dollarverse
FR - pcs in the army of Lashan of Scardale, assaulting the tower of the Tyrant-Sage of Shadowdale.