I am wanting to run a campaign that is a rip-off of the Hunger Games (the arena death-match bit, not the deciding between two love interests or revolution aspects).
I'm looking for a set of game rules that meet the following criteria.
Has good, in depth rules around natural hazards; thirst, hunger, cold, sleep deprivation etc.
Both the natural hazards and injuries from combat should have in game effects that reduce your effectiveness before death occurs.
Some system of weapon proficiencies, where people are significantly better at a small number of weapons, and slightly better at weapons similar to that small number of weapons.
Medieval tech required. Bonus points if it also contains rules for modern/sci fi level tech.
The group mostly dislikes PvP, so I am intending to have this as last group surviving wins, with all the PCs in one group. There would then be the potential to form temporary alliances with NPC groups, which would start at a similar size.