Help you help them help you help yourself.
Overwatch is a game about a group of Rebels working-together to overcome a force vastly more powerful than any of them. As such, lone-wolf tactics are not only suicidal, but leave your team one member short in a game where every person counts. The basic dynamics of working with a team are not that complicated and boil down to: Help your teammates, stick-together. If this mentality isn't enough for you and you need specific tips, I can deliver.
Firstly, there are two ways to be helpful, and the true Rebel will know when to switch from one to the other:
There is the benefactor, who is helpful no matter what. He puts everyone else above himself and is generally nice.
There is then the selfish helper, who helps others help him. He may not be as likable as the benefactor, but done correctly he can potentially be much more helpful than his counterpart.
Basic tips:
- You must trust your allies. You are not the only one with a gun and your bullets aren't very helpful if you're too dead to use them. However...
- Your death is not the end of the game, but it is a major setback. With this in mind think of death as a tactical decision rather than a loss condition.
- There are times when going Rambo is actually a good idea. Should the Rebel group be overwhelmed, someone can take one for the team and rush the most vulnerable objective alone. About half the time the Overwatch will panic and send his troops out to stop you specifically; this should give your allies time to regroup. If you are going to be incapacitated rather than killed, either die somewhere where the others will stop at anyway (like the objective or a resupply area) or insist they not revive you.
Defender tips:
- The Defender is basically the ability to "take one for the team" without actually "taking one for the team".
- A good defender should be very irritating to the Overwatch, whenever it spawns troops, he's right there with that shield out so the Combine soldiers can't do anything.
- If not playing the Defender, camp behind him and be his guns. Shoot over and around him to get rid of the Combine he's blocking so he can be free to be helpful elsewhere.
- If you are near the Defender, kill the Manhacks. There is nothing more annoying to the Defender than having Manhacks poking him in the back while he's saving your sorry asses from the legions of Combine he's denying.
Medic tips:
See Warbrand's Medic Guide for good tips. If you want my input, though:
- PAY ATTENTION! There have been comics in monument to how much people hate dawdling Medics.
- Don't pick-up the Mid-Kit unless you have at least 90 health. The healing ability recharges twice as slow when you are regenerating. If you absolutely need to, try to find health kits to bring you to the recommended health.
- The useful Medic should not only dodge death, but dodge damage entirely. Even the slightest prick can literally halve your ability to heal your teammates.
- As far as the Medic is concerned, the Overwatch Defender is the TF2 Heavy. Even with that shield he's bound to take a serious beating if he does his job properly. That means you should be healing him whenever possible, but be sure not to ignore your other teammates.
Worst Case Scenario:
With our wonderful, small community, this is very doubtful. But later-on this will be a common occurrence: One of your teammates is a useless, screaming, swearing, 10-year-old (or a griefer). At this point the most useful thing you can do is pretend that he isn't actually there. He will do something eventually, and any effort you put into helping him is essentially wasted. Its much better to concentrate on those who can actually do something for the team. Do your best to beat him to any role items that may be present or you can consider that role gone. Should he successfully take a role item, kindly ask him look at you and press "h". Should he refuse, you'll just need to grin and bear it until he dies, at which time you should just take the role item and leave him be.
Should your entire team be said children (and/or griefers), grab a riot shield and do your best.