Yeah, ten might be too much, but you want people to have at least several so that there can be bidding. Maybe five instead? Or "(Number of elements you want + 2*number of players)/(number of players) so there can be bidding.
Most superhero campaigns have a strong element of "like our world but..." so you're just talking about elements you want to see that night. (Yes, some of them might be background elements, but keeping it open like that is part of what I like about the idea: one group with "mutants" and "ninjas" comes up with a background where the mutants are persecuted in secret and destroyed by human-supremacist ninjas and the other comes up with the concept of a group of mutant ninjas. Both are good.)
The idea of selectng from the shock table might work, too.
It's also okay to roll up on the random adventure table and say, "The setting is Earth As We Know It But With Respected Supers. Let's go!"
Or have a random table (probably not a useful table, but ideas):
2d6 Roll Element
2 All powered people are persecuted
3-4 A subset of powered people (e.g. mutants) is persecuted.
5 Heroes are not trusted
6 All superpowers have a single source
7 Super attacks are lethal unless specifically stated otherwise
8 Heroes are trusted (there are mask so they can testify)
9 The super-geniuses are not useless and are changing the technologies of the world
10-11 The heroes specifically are persecuted
12 A villain of some stripe rules the world
John McMullen (Searching for a .sig)
From: Cameron Mount <cameron.a.mount@...>
Sent: Friday, December 7, 2012 10:52 AM
Subject: Re: [icons-rpg] The universalis world-building technique and ICONS
I've not tried that (or what I'm about to suggest). Have you looked at Joshua Newman's Shock: Social Science Fiction? It's a GM-less rpg, but the specifics aren't really important since what you'd really be looking it is pulling the Shock chart into ICONS. In Shock, players call out different "cool" ideas and the coolest is the major difference between our world and the sf world being created. Something like "Mutants!" would be the shock, and then players take turns coming up with issues, like "scarcity" and "colonization." (to an extent, that's the basic background for the Schwarzenegger version of Total Recall).
Joshua's guidance is "if someone’s excited about it, go with it. If no one’s excited about it and someone says no, move to the next idea" which may not necessarily work, which is why a round-robin, the way you suggest, is at the key, but I think you're on a roll with the idea of bets and wagers for inclusion of specific elements.
I think 10 determination might be too much, but that's a playtesting number to try out.