Board Thread:New on Survivor Wiki/@comment-11184708-20130624063859/@comment-17033034-20170802152259

Tribes don't switch and don't merge until there is one remaining player from the opposing tribe. So if there's two tribes of 10, the earliest merge could be at the Final 11 (10 from one tribe, 1 from other tribe) Kind of like Palau, but an on-purpose conquering. The goal would be to conquer the other tribe.

Also, Survivor:Rivals

10 returnees come in on a helicopter and await their other castaways. But then their Rivals come out from behind the bushes and surprise them 

But also there could be people like Shane vs. Courtney, Sierra R. vs. Tyson, Shambo vs. Laura, Alicia vs. Christina, The entire cast of Philippines vs Abi, Woo vs. Abi, Marisa vs. Brad, Kass vs. Trish, Baylor vs. John Rocker, Rodney vs. Mike, and a lot more!