I will not judge the winner at all.
At the end of the game every user will be able to see the result. The system is not like dice sites or casinos..
You killed x amount and stayed at position 1 and others will follow at descending order. If someone killed more than you, you will go under him.
Ok, so something like a shooter of a kind. How can you prevent people cheating? There are aimbots and hacks made for almost every single PvP game in existence.
What if someone auto aims or uses external software to increase their chances?
Players have to play well to stay at the 1-10 position to win prizes.
Lets say, if you have played very well at the beginning and your position is at 5 then after 10 mins you went to the position 15.
Every second you can monitor your position. The game time will be 30 mins. So after 30 mins the game will end automatically and the result will show up instantly.
Anonymous? I will be the referee.. Everyone can find me here everyday.
If I start the game with 24 players, then as 25th player I will join the game as referee, not as a player.
Will you be able to influence the outcome of the game? In a game like that a referee's job shouldn't be required. You either kill someone or not. The rules should not leave any doubt so that there's no need to ask for referee's decision. If you allow for that there will certainly be some accusations. The more complex the game the more rules you'll need to establish. Like in chess the rules are very simple, but compare it to a competitive moba game and you'll know what I mean.
The game has no hacks & cheats. The game only depends on skills. I am playing the game since 4 years.
I will not be able to influence anyone by any means. Only player's skill can help them to win. Better players play, most probably they will win.
If I start the game then the necessary rules will be made to establish the game, but I will try to keep as simple as possible.
Regarding referee's duty,
As I will organize the whole game from first to last. I have to give assurance of players winnings in a fair way.
I mean, as a organizer my duty will be to hold the bets made by players. Then distribute the funds to winners as mentioned in OP.
If I don't join the game as a referee then how I will announce the result? If I ask someone else to announce the result then it won't be authenticate.