Online multi player games are today one of the most popular entertainmentservices. This rapid growth attracting not only the players but also the researchers. First Person Shooter game is one of the most popular online game. First Person Shooter games are very sensitive to the disturbances in the network. So, the e ects of di erent network parameters should be studied and analysed clearly to provide better Quality of Service to the end user. This work analysed the impact of Packet Inter Arrival Times on the game playing experience of end users. To do this 57 experiments were conducted between 2 to 4 players in a famous LAN party, Dream Hack Winter 2007. The game played in the experiments was Battle Filed -II. NetEm network emulator was placed between the game server and the player machines to imitate the real time behaviour of the network by introducing disturbance in the form of delay. After the proper analysis of all the collected data conclusions are made by stating that there is very minute impact of constant delay (with out any variation) on Packet Inter Arrival times.