At any time during a round (except sudden death), you are free to change you class without dying so long as you do it in your spawn area. So if you’re defending your base as a sniper but you are getting overrun to the extent that you are unable to be effective, you may consider ducking back into your spawn and respawning as a heavy. The same applies for sudden death, only with the exception that you can only change your class within the first 10 seconds or so of sudden death, after which you are unable to do so. It is incredibly wise, at the beginning of the sudden death round, to change from a weaker class (such as scout) to a class with more health and better defensive capabilities (such as the soldier, heavy, or medic).
If your team has less than 2 medics, for the love of all that is holy, please consider going medic yourself. People seem to think that the medic doesn’t get points, and that being a medic is like “taking one for the team,” but honestly if you have no medics you will lose, and if you have 2 medics you have a fighting chance. The more medics you have (up to 3 or 4… you can have too many) the more effective your team is, since your front line troops die less often reducing their need to respawn and ensuring you always have more troops available. If you have more troops, you should be able to defeat the enemy more comfortably, meaning your troops will get more kills, meaning you get more assists, which ultimately translates into more points, for you and the rest of your team. Do the right thing, be a medic.
If you want to be healed by a medic, it’s no use simply shouting medic repeatedly and expecting to be hunted down by one. You’ve always got a better chance of getting healed if you run to a medic and stand in front of him (or at least where he can see you) having called medic at least once. I will always heal someone who comes to me, but if they expect me to go to them, especially if I don’t know where they are, I usually just forget about them. Note: it’s possible that they are in fact on about 2 health and hiding for their life behind a rock. In this case it’s your duty to go paramedic and help them out.
Communication in Team Fortress 2 is critical. Talking over a microphone is the best solution, but if you don’t have one or aren’t using it, make use of the in-game communication. You can encourage your team to push forward with z4 (“Push up!”), or if you’re a medic with an übercharge ready (or paired up with one) you can look at your buddy and say z3 (“Go go go!”) or x8 (“I am charged!”) indicating that you’re ready to übercharge. Or, if you’re the spearhead, reloaded and ready to be übercharged yourself, hit x8 (“Activate übercharge now!”). And of course there’s c1 (“Help!”) which you can use when you’re under attack or capturing a control point by yourself. It may seem as though no one can hear you (or wants to hear you), but if it results in just one person coming to your aid, it’s better than nothing. Not to mention it gives the team a clearer picture of what’s going on, whether they take action or not.
If an engineer on your team hasn’t built teleporters or maybe has built and entrance that doesn’t have a matching exit, remind him nicely that maybe it should build them. Sometimes an exit gets sapped while the engineer is engaged in a fire fight and is so distracted that he simply forgets about the exit. In this case reminding him to rebuild it should result in an exit within 30 seconds that will once again assist your entire team.
In capture the intelligence maps like 2Fort, the briefcase icons in the middle of the bottom of your HUD show a house if your intelligence is safe, an exclamation mark if it is in the possession of an enemy, and a downward arrow if it has been dropped as is sitting around. In addition something I didn’t realise for quite some time is that the triangular arrows that spin around the circle that is the briefcase icon act as a compass, pointing to the current position of both your and the enemy’s briefcase. If your briefcase has an exclamation mark (stolen) or down arrow (dropped), line yourself up with the triangular arrow, find your intelligence and defend it until it returns to your flagroom. This should be a top priority for every class, since every time the enemy picks it up, the return timer starts again after they drop it.
In any map, but especially the linear control point maps like Well and Granary, make sure your team is always on the offensive as much as possible. The only way to win (excluding the dodgy sudden death) is to capture all the control points, so there is simply no reason to sit in your base all map assuming you can’t win just because the enemy controls the middle point. Your team should be putting the full extent of their effort into gaining or regaining control of that point, for the reasons discussed in my veritable lecture on map control. Often the middle point is simply left undefended, and after the team on the back foot fights off a wave of attackers they sit around and lick their wounds, where a combined push forward would result in an almost certain capture. One day people will realise the advantages inherent in controlling the map and this will be their top priority, but until then I’m just going to keep repeating it.
On control point maps, especially ones like Hydro (or the second CP of Dustbowl) where losing the point means losing the round, the enemy is unable to capture your control point so long as someone from your team is standing within the capture zone. Therefore it stands to reason that if they are capturing your control point every nearby player on your team should make every effort to get into the capture zone, not stand just outside and shoot grenades or rockets like I see so many people do. Get in the zone and then unload your weapons, or even just bust out your melee weapon, since they are probably on low health having made it all the way through in the first place. People seem to think “if I go in there he’ll kill me!” so they don’t go in, so their team loses and they get gunned down in the after party anyway. This applies to control point C on cp_Gravelpit as well: if the attackers get anyone inside the capture zone, ALL nearby players should rush to get in there with the enemy and stop them, even if it’s a pyro, though in that case you may have to improvise. Don’t be afraid to rocket or sticky bomb jump to get into the zone if you’re a long way away/below.
On all stages of Dustbowl, where the attacking team stands behind the gates during setup time, don’t stand right up as close to the gate as you can and all but tell the enemy where you’re coming out. It may be a minor point, but there is simply no reason to give your opponents any more information than is necessary.