Idea: Succession fortress "Capture the flag".
x2 "teams" (each one a different civ, to prevent migrant crossover, +1 civ who are the "Temple builders".)
Setup: Using a neutral civ, Game host makes nine 3x3 embarks somewhere in the world map. On each embark, he builds a "Temple", makes it a temple zone, places a statue in the temple, then retires the site. (These embarks should be scattered across the world, in really inhospitable places). After retiring the last Temple, use legends mode to export a landscape map minus the civs and post it to the forum so teams are blind to each other's starting placement as well as where the Temple sites are.
Each team then chooses an embark spot somewhere on the the world map, and PM's its location to the game host, who sets up a 3x3 embark on that spot for that civ then retires them. Each team will get a different civ to prevent migrant cross-over, also, I wouldn't bring any drinks because those go away every time a site is retired.)
Teams then take turns playing for one in-game year building up their respective fortresses, making sure to set up a "Treasure Vault" area to store the "flag" once its captured, retiring the fortress each time before passing the save to the opposite team.
Game play:
Each team creates then retires seven adventurers at their respective forts: these are playing pieces. Alternating team members unretire one of their own playing pieces and use them in-game until sunset of that day before retiring them once again. If a playing piece is killed, that team just has one fewer playing pieces. The goal is to grab the statue from the one of the temples (first one at a temple to do so, gains a curse from "defiling the temple"), and get it to their team's Treasure Vault. Each playing piece may only by moved until sunset, when they must be retired somewhere. After that, play returns to the opposing team who gets to move one of their playing pieces until sunset when they retire it or "give in to starvation", and so on until every person on each team has had a chance to move a playing piece. (Adventure mode even in a large world lets you cross from pole to pole in a week or two. Limiting adventurers to one in-game daylight period allows teams to strategically move their playing pieces to counter opponent's moves.)
Points are tallied up at the end of each round:
+1pt per team's surviving playing piece
+10pts per Temple statue in a Team's Treasure vault
Game ends when either one team's playing pieces are all dead or all the statues are in the Treasure Vaults.