So, here are my ideas for quarter quells, had the rebellion failed. I'll say the first three that have been used in the books first.
25: tributes will be voted for by the districts
50: twice as many tributes will be reaped.
75: the tributes will be reaped from the existing pool of victors.
100: instead of children tributes, adults will be reaped
125: no supplies in the arena, everything comes from sponsors
150: no food will be put in the cornucopia, tributes must eat or be eaten
175: no weapons will be in the cornucopia, tributes must use their bare hands to kill
200: capitol children will be reaped
225: no cornucopia, all supplies are hidden throughout the arena
250: three times as many tributes will be put in the arena
275: parents will be reaped
300: Each tribute is tied to their fellow tribute for the entirety of the games. One dies, so does the other. But at the end, they have to kill eachother.
325: parents will be reaped, and must choose one of their children to take with them (I know, I'm evil)
350: boys vs girls
375: boys only
400: Capitol Citizens vote on what happens
425: no volunteers
450: victor's relatives will be reaped
475: instead of ages 12-18 being reaped, ages 5-11 will be reaped
500: girls only
525: the tributes will be siblings
550: Dead tributes bodies will be reanimated for a zombie hunger games
575: Zombies of dead victors
600: arena is in complete darkness
625: district victors decide who the tributes are
650: two hunger games this year
675: no sponsors
700: one district will be randomly chosen, and THEY will provide the required 24 tributes
725: only children from rich families can be reaped
750: children with disabilities are reaped (I feel evil for coming up with this)
775: tributes aren't allowed training before they go into the arena.
800: one tribute is chosen, and they must choose their partner.
825: an all water arena
850: the arena is divided into 12 sections, each one resembling a district
875: the entire arena is underground
900: the arena is a giant labyrinth.
925: the tributes can't kill eachother, an unstoppable predator is released into the arena until only one is left
950: four times as many tributes will be put in the arena
975: the arena is a lava world
1000: An exact replica of Panem is made on the other side of the world, down to the very last detail, with the cornucopia in the capitol, and tributes must go through that to kill eachother. Ten times as many tributes will be reaped. When all tributes from their district die, that replicated district will explode after one day