I would really like to have a graph as you can see on the picture below. But I do not have any idea how I can realize this with latex. I am sorry for asking you like this, but I am quite new with this stuff. I hope someone may help me. Thank you!!
Source of the picture: http://www.uni-saarland.de/fak1/fr12/albert/files/ss07/Spiel-Kap2.pdf