How do I make a 2 player game?

I want to know how to make a game where there are two players using the same computer. One player uses WASB controls and the other uses the arrow keys. I wanted to make a game where the two players fight each other.

You create 1 character for player 1 that responds to the wasb controls only, and a second character for player 3 that responds to the arrow keys. This way, they can use the keyboard and play together at the same time.