REMEMBER WHY YOU ARE IN A TEAM

My final thoughts on this are less technical: remember why you got into team-gaming in the first place, it is more interesting and challenging to achieve something with other people. Team-players defy the imagery of the gamer by immersing themselves in a highly social activity, this is an activity that benefits you past your experience in the game – you actually have the opportunity to make new friends, and maybe even close ones.

Ultimately, you need to play because you desire to, and as long as this is true and you surround yourself with like-minded individuals it will be a meaningful experience which you can cherish past your gaming years. Teamwork with others is special, intimate, and don’t forget that.

INDIVIDUAL PERFORMANCE AND RESPONSIBILITY

This emphasis on communication means that you are no longer only dealing with your desire to get frags and win the free-for-all match. This means you will now start dealing with the desires and feelings of others. Ultimately, this amounts to another responsibility each team-player is bestowed with upon joining the team. Watch yourself. Being in a team means you are dealing with other people’s time, people whose intentions and desires you find beneficial. You need to coordinate yourself both in-game and outside of the game, giving your team a clear idea of how you would feel comfortable competing.

If you allow yourself to get beaten down, or to beat on others in the team, it would only serve to you and the rest of your team’s detriment. In this way, it quickly becomes clear that a team is only as strong as each and every one of its components.

COORDINATION

If objectives are the goal of each round, and communication is a means to obtain it, then from that we get coordination. Coordination is what arises out of the ability of each member to constantly communicate information relevant to the enemy’s strategy.

This is the heart of teamwork, when a player joins a team this immediately becomes an important skill – one that must be regularly practiced. Each player now has the responsibility to get involved in the team’s strategy. This means each player taking the command partially, and it the captain will be left to judge whether these commands are relevant or not.

Through this method the team can hone their coordination and by that their teamwork

COMMUNICATION

This must be the most obvious activity of team-based competitive games. So there are five of you on a team, the least you can do is form some kind of basis of communication which doesn’t require a member to be dead to receive the messages: Voice-over-IP (VOIP) applications such as TeamSpeak or Mumble come into play.

The less obvious part is this: what do you say?

Communication is a goal-orientated action, especially in this context; therefore what first needs to be kept in mind is the goal of the game. For us MW3 players this is called the objective: stop, defuse, or plant the bomb.
Now we need to figure out how to use our communication in a way which serves our goal or objective. This is where I diverge from the obvious. For most, calling the position of each member’s attacker is sufficient. In this way, communication servers as some kind of radar extension. I see this necessity differently: you can do more… To obtain more control, it is my belief that each member must do as much as possible to alert the team of possible dangers which would ultimately obstruct the team’s ability of securing the objective. This means that each player has a responsibility to play the game but also to help command the team. This is of crucial importance and I believe this possible use of communication is often over-looked. This means that a player can call much more than the location of enemies, he can also call the lack of location. If an enemy team is completely missing from one side of the map, this is a crucial piece of information which would warn the team of what is to come on the other side of the map, yet this warning would not happen if we take a narrow understanding of what communication entails in-game.

Quoted from http://bravadogaming.com/guides/modern-warfare-3-and-teamwork-explained

http://gaming.do.co.za/helpdesk/index.php?/Knowledgebase/Article/View/59/28/general-league-rules