The following guide was written by reddit user and TF2 player Tokell, who has graciously given us his blessing to feature his excellently written zero-bullshit guide on how to play the Engineer like the best damn good ol' boy from Texas.
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I don't main engineer, but I play it enough to consider myself a damn good one. And after playing with engineers so mind-numbingly bad that I wanted to change teams and kill them, I thought I should share some tips.
Defensive engineers
Steps for building your first sentry nest!
• When the round begins, you should already have your PDA open before you can move.
• Once you can move, drop a teleporter IMMEDIATELY outside the entrance that most people go through. Not halfway to the point, not behind a fucking rock hidden from view. Right out where everyone can see it, and can defend it from spies as they run past.
• Turn around and go back to refill your metal, and drop a sentry right next to the teleporter. Go back and refill your metal a second time, then whack the sentry to make it build faster. Do this to all your buildings, because beating things make them work faster.
• By this time, less than 10 seconds should have passed. You now have a level 1 sentry that you can pick up and take to the point, leaving you with 200 metal to upgrade it. This method works best when the walk to the point isn't excruciatingly long, as you walk a little slower when carrying things.
• Pop that sentry down in a spot that covers the point, but allows you to hide behind it and whack it. The area shouldn't be out in the open, and should be where your teammates can rally around to defend the point. Long hallways, windows into rooms, and ledges work best. Try not to put the sentry where it or you can be taken out from across the map. You'll notice a sphere out in the distance while carrying a sentry– this shows you the range. It's best to put any entrances at the very edge, so the sentry can react instantly, but is too far away to take any hard damage.
• At this point what you do next depends on the number of ammo packs around. If there are plenty, pop down a dispenser and teleporter behind your sentry, and then upgrade your gun as fast as you can. If there aren't many ammo packs around, focus on getting a level two sentry before anything else.
• Upgrade your teleporter next, then your dispenser. A teleporter that leads right next to your nest is vital, as it's defended, and gives you a steady stream of teammates who if nothing else, will distract the other team long enough for your sentry to kill them instead of killing you.
• Congratulations, you've got your first nest!
Random tips now!
• When setting up your nest, NEVER stand on a teleporter that's turned on, and try to not keep your back turned to it for long. If a spy comes through it, they will telefrag you if you're standing on it, or get an easy backstab while you're staring at your sentry. A good spy will sap your sentry, then stand on it in an attempt to frag the hapless engineer who jumps atop it while trying to save his stuff.
• Building two sentries next to each other is the absolute worst thing you can do, and everyone WILL hate you. There is no point to it. Two sentries cannot take out anything that one sentry can't. If defending a point instead of a chokepoint, set your sentry up just within range of the other nest so you can defend each other, but never build them close. This also prevents ONE demoman from taking out the entire defensive line with four stickies.
• Never put your dispenser behind you. This prevents spies from sitting behind it waiting for the perfect moment to stab you, and prevents anyone else from hiding behind it to frag your shit. Your sentry can't see behind your dispenser. Cloaked spies will also recieve metal from the dispenser that recharges their cloak, so frequently reach up and whack the air above it. You'll occasionally find a spy sitting up there thinking he's a genius.
• If you see someone staring at your sentry, fucking shoot them, because they're usually a spy. Most players won't look at your stuff as they come to get health. If you suspect someone's a spy, shout it out over mic, don't just sit there and wait for them to come to you.
• Your sentry can survive long enough for you to kill that spy sapping it, if you manage to take them out with just one wrench hit or two. You might lose one building, but you will have time to save the rest if they were at full health. If no one is there to kill the spy for you, you will lose a sapper vs. wrench war.
• If there's another engineer set up nearby, check his nest, constantly! If he can see you on his deathcam just staring as his stuff gets sapped or blown apart, he will hate you. Take off that sapper, repair and upgrade his stuff. Because otherwise he's going to come over and take your metal to rebuild it, and then you're left with jack shit as he builds his nest back.
• Wrangler tip. If your sentry is taking damage or is about to get stickied to hell and back, wrangle it. This will give you a sudden 500 extra damage to soak up, giving you enough time to whack it back to health, or to survive that uber demo that just came in. It's a good idea to run away at the same time, as the shield doesn't keep you from getting blown up instead.
• An advanced tip. If your nest is too close to the spawn to warrant a teleporter, use those teleporters as early-warning systems. Put them on stairs, in doorways, etc. Most noob spies will happily go around sapping the fuck out of them, giving you precious seconds to turn around and wrench them in the face before they even get close to your sentry.
• Another advanced tip. If you see an engineer up on a ledge without any way to get up there, he used his sentry to rocket-jump there. These places are usually easily-defendable and good points for a sentry, but require teamwork to pull off during setup time. Beg the other engineers to not take all the metal and help you get just one sentry up so a teleporter can be put in the hard to reach spot, allowing them to flood up there.
And a tip for everyone who DOESN'T play engineer.
• During setup on defense, if you're not a medic then you should be an engineer, helping the actual engies set up their stuff. Having an entire level 3 nest set up before the round even starts is very powerful and not usually expected. Don't be afraid to use the suicide command to die and give the engineer extra metal, as long as you have time to make it back to the front as your proper class. It's not Call of Duty, there's no KDR.
