The game's pretty simple.
Someone will be on top of the hill and claiming it as his'/her's. Now the others will do everything they can to get the hill and claim it as their own.
For example:
Player 1:
Set up a flag on top of the hill. My hill!
Player 2:
Bombards the hill with nukes and firework crackers. Detonates it... boom! My hill!
Player 3:
Snipes Player 2. My hill!
...and so on. Let's start.
Sets up a perimeter of javelins at the base up to the top of the hill. My hill!