Engineer match-ups

Class			Strategy
Engineer	vs	Scout	A Scout is a more threatening opponent when on your own. A Scout is much like you in many regards: same hit points, similar weapons, similar hit box, except Scouts are fast, agile, can jump high, and are hard to hit; you're not. Try and stay out of point-blank range, and blast them with your Shotgun while avoiding their Scattergun shots. If you are using the Gunslinger, placing a mini-sentry can provide you with a firepower boost or distraction, either killing the scout or causing him to flee. It is better to avoid direct combat with an experienced Scout as their Scattergun can do much more damage than your Shotgun. When with a Sentry, you can relax, as it will mow down any Scout with ease. While scouts cannot dodge or outrun the bullets (as you might think from the Meet the Scout video) of a sentry, at certain ranges they may be able to run to cover before the sentry can turn to face them. This can often be avoided by placing the sentry so that its normal 90° sweep covers the right area. If put into small rooms and around corners (like the intel room in 2Fort) you can rack up easy Scout kills, who will be forced to get another classes help. Scouts using the Bonk! Atomic Punch unlock can be a threat. They can either use it and run behind you or your Dispenser, either making your sentry kill you or making it not even shoot if the Dispenser is blocking its line of sight. Just pay attention and kill the scout as soon as he isn't invincible to avoid any unnecessary hassle. Scouts can also be a distraction, forcing your sentry to turn around and allowing the other team to get an easy kill on your sentry. If you have the Wrangler, you can redirect your sentry fire onto the players attacking your sentry making the distraction useless.
Engineer	vs	Soldier	For lone encounters with a Soldier, don't try to fight unless he is severely weakened or you know you can safely take him out with a single blast with your Shotgun. It is safer to run, or lead him into your Sentry. Be wary when guarding your Sentry, as Soldiers can use their Rocket Launchers to destroy an Engineer's equipment with a volley of successive shots. They can even destroy your sentry from very very very long range with their rockets. Keep it well repaired, and be sure to place yourself behind it to minimize taking splash damage from rockets. If you can, help your Sentry do its job by firing on the Soldier with your Shotgun or Pistol. With the Direct Hit,the soldier becomes a larger threat,because he can sometimes one-shot you at close range, while being able to take out a fully upgraded sentry with two shots. It is almost impossible for a Sentry Gun to survive bombardment from two Direct Hit Soldiers. In the case of a soldier bombarding your sentry with Direct Hit rockets,your best bet is to ask your teammates to take out the offending soldier,who will mostly likely remain fairly still, due to the small splash radius requiring greater aim.
Engineer	vs	Pyro	When on your own, stay out of range of a Pyro's Flamethrower and blast away with your Shotgun, or, at longer distances, your Pistol. However, if you have a Sentry, it should be able to mow them down quickly before they can get within effective range. Try not to place your Sentry so it hugs a corner as this allows the Pyro to take it out without entering its line of sight. Bear in mind; if pulled off correctly, a skilled Pyro can circle strafe to take out a level 3 Sentry, you, and all your buildings without dying. So long as the Pyro isn't allowed to get your sentry into the range of its Flamethrower, it won't be a threat to your building. Also take note that if your sentry is close to a corner, but too far to edge, remember that a Pyro's high damage output can occasionally allow him to charge towards the sentry and take it out, though he'll be heavily damaged. Keep an eye on your health if you catch fire, and retreat to a health source such as your own Dispenser if your life is in danger. The Homewrecker is worth mentioning as it does twice as much damage to buildings than any other standard melee weapon. It can destroy any building with only 2 swings if you allow the Pyro to get into melee range without dying.
Engineer	vs	Demoman	Like Soldiers, Demomen are a very dangerous class for an Engineer and his Sentry. They can lay down sticky bombs and grenades while staying out of your line of sight, which can take both you and your Sentry down quickly. Sticky bombs are especially deadly to your buildings; to remedy this, try and avoid placing your Sentry around a corner or in a vulnerable position. Breaking the stickies, though possible, is not recommended, as the Demoman will usually detonate them before you can remove a sufficient amount. If a Demoman is about to sticky your sentry, take the fight to them with your Shotgun. Try to get into his face since a sticky launcher is useless at point blank. In a one-on-one fight, stay at medium range while blasting away with your Shotgun. Don't hesitate to run if there's no hope. If you care about the score, you can even destroy your own buildings to deny the enemy Demoman his points. If they have a shield instead of stickies, they are less threatening to your Sentry Gun. The Targe will only protect them from level 3 Sentry rockets. Take note of Demomen using the charge to bypass your Sentry and hide behind something where they can lob grenades at you and your sentry.
Engineer	vs	Heavy	A Heavy can use the high rate of fire from his Minigun to destroy a level one Sentry, and even take out higher level Sentries when paired up with a Medic. To remedy this, stick with your Sentry and keep it well repaired until it takes out the Heavy, and hopefully his Medic partner as well. Some heavies may try to shoot at your sentry while remaining safely around a corner, if this is the case, just keep it repaired until he runs out of ammo, then go at him with your Shotgun or Pistol (if he has the Sandvich equipped instead of his Shotgun, he will be almost completely helpless as long as you keep out of range of his Fists). If they are ÜberCharged, do your best to keep your Sentry repaired until the charge wears off. Your best bet is to use your Sentry as a shield as you repair it with a nearby supply of metal. Coordinate with teammates to push the Heavy back with explosions or Compression blasts. Due to the Heavy's slow move speed, it will take him a while to move back, giving you more time to repair. If it is clear that you cannot save your Sentry, it's better to run, and live to fight another day. In a one-on-one encounter, it is best to flee, as a Heavy will likely mow you down before you can take him out with your Shotgun.
Engineer	vs	Engineer	In the very rare situation that you find yourself in a one-on-one encounter with an enemy Engineer, simply blast him with your Shotgun before he can take you down with his. If you find an unattended Sentry, it is possible to use a Scout corner creeping Pistol strategy on it. If there is an enemy Engineer maintaining it, inform your team about its whereabouts and let your team deal with it.
Engineer	vs	Medic	Medics, alone, are cannon fodder for your Sentry, but when using an ÜberCharge, they can spell danger for an Engineer. Simply keep your Sentry repaired until the charge wears off and it will hopefully take out the Medic. Sentries have very high pushing power, but a medic can go in front of his patient to take up the push back and allow his patient to finish the sentry off. Should the Über-team come close enough to put you or your sentry in terminal danger, bail out immediately and prepare to rebuild when the action dies down. In a one-on-one fight, avoid their Syringe Gun shots and Bonesaw while blasting away with your Shotgun.
Engineer	vs	Sniper	It should be rare that a Sniper is within close enough range of your Sentry to be killed by it, and on maps where it is more difficult for a Sniper to reach your position, you can expect to see very few of them. On more open maps, however, a Sniper is more dangerous as he can stay out of range while damaging your Sentry with charged Sniper Rifle shots. To solve this, stay with your Sentry and keep it repaired. It is possible to shoot a Sniper with your Sentry beyond it's range by controlling it with the Wrangler. At close range, blast the Sniper with your Shotgun, while avoiding his Kukri and Submachine Gun shots. The Level 3 Sentry provides modest cover from headshots, but at times you benefit most from setting up in a spot safe from sniper fire. Be sure to alert your team when a sniper targets your sentry. You can use your Pistol to mess up his shots if your not under any other threat.
Engineer	vs	Spy	The Spy is the Natural predator of the Engineer. Engies really, really hate spies. A skilled Spy in disguise and his Sappers can act to counter you, but as long as your teammates are around you and you're alert, they shouldn't pose as great a threat as they would do. Spy-check anyone coming within range of your Sentry, and listen carefully for the decloaking sound that Spies make. If a Spy places sappers on your equipment, your top priority is to remove the Spy, either by yelling to your teammates for help or blasting him a few times with the Shotgun. When he saps your sentry, you can expect he'll attempt to backstab you to prevent you from removing it, as by the time you respawn, your buildings have a slim chance of still being around (unless an Engie or Pyro buddy saves them). Try to position yourself so that you can see the spy as you are whacking the Sapper. If you can see him, he can't backstab you. If you prevent him from backstabbing you long enough, help will have likely arrived. When the Spy is no longer a threat, remove the Sapper immediately (by hitting it with your Wrench) to prevent further damage and repair. Be warned that a Spy can sap faster than you can repair, so if you don't take him out, he will eventually destroy your equipment. To prevent surprise stab-saps, it's useful to glance over your shoulder between Wrench-swings as you build or repair one of your buildings If a Spy saps a structure when you're too far to save it, inform your teammates and keep your guard. Remember that the Spy is much less effective when your team is actively pursuing him. Never stand on, or even near your teleporters, even when you need to whack off a Sapper, Spy's can telefrag you and sap the rest of your stuff. Ask a Pyro to protect your buildings as the Pyro is the best Spy Checker you can have.

---