How would I make a game like Fencing?

I have tried and tried but never EVER have been able to make a game sorta like fencing. Like a different arena and plate size but I mean really. HOW?! I can make the arena perfectly fine including the plate that the swords do damage on, but have never understood how to script it. And I'm not sure whether I should insert the script into the swords or the arena plate! Please answer.

arena plate and instert the other arena plates if not and you only have one arena you should put it in the sword(btw roblox doesn't allow meshing)

Luckily, cantkillme provided an algorithm for this.