Small (mobile) game networking

Hi,

there are many solutions for networking. I have developed a FPS authorative solution for Unity3D. Now we are looking at smaller games, 1vs1, for iOS and Android, preferably cross platform supported.

In order to do some sort of protection and also logic, I think a server is needed. Solutions like Photon offer a "serverless" connection through their services, so no server is involved.

The problems I run in, mostly logic wise, is how do you guys solve these "problems"? What if you have a 1vs1 shooter for example, and someone throws a grenade that explodes when it hits something. It is send at tick 1200, yet arrives at tick 1300. One of the two machines has to detect and register a hit online, and then the server can do proper highscore calculation.

I come from the thought of beeing somewhat authorative and having a middleman at least calculating hits and points, so right now it feels that if one of the clients does hits and registers them, it feels like a very fragile construction.

Does anyone have any thoughts on the subject they would want to share, and possibily how some solved these situations?

Kind regards!