For the record, do be a little warned. The BYOR will be run by the same person that put ROLES into a Mountainous game.
aka: I can NEVER do anything normal.
The quirk (might) be small (or large) for BYOR: Choices though. During signups there will be a list with lines like this:
Just a Dot, Not a Lot
Show and Tell
Mightier than the Sword
Each one corresponds to a rule that can be placed in the game. Along with the normal 'give me a name' (and yes, links/videos/whatever can be used to explain your role's name here though I CAN go odd with how I spin it) you can request as many or as few of the rules as you like. Any rule that has at least half the players choosing it will go into effect. The rules won't be bastardish (OMG your vote goes to the one below you!!), just changing the style of the game and the roles that will be given. i.e. "spoiled flavor" means that the flavor will have actual game information (think how Paranormal's flavor goes) and some of the roles will have abilities that touch on it. "..in the membrane!" means there will be roles that effect sanity (i.e. scum that can make a player Insane, a doc that heals sanity..ext).
You won't be told directly what line does what but it can be reasoned out if you're that type. You'll be told what rules are in effect when the game starts.
And if you're afraid, the game works as a standard game. It's just a matter of adding quirks depending on what the players desire.