Even if you're Texan, you're not Tex Willer, you're not John Marston , you're not John Wayne in one of his movies. You can't jump on the battlefield shooting everywhere. The Heavy can, unfortunately you have only 125/150 hp. Your best allies are your ( mini )sentry gun and your dispenser. Also remember that you can be damaged and killed by your own sentry, so, be careful. You main goal is to support your teammates and to avoid get killed while moving your gear up.
Your best allies : Demomens,Snipers,Pyros, Intelligent engineers and Heavies.
Your worst enemies : All classes. ( Yeah,not kidding about that ).

These weapons are obtained after you had been achieved some of Engie's trophies.

Even if you equipped the Wrangler, you can't pretend to be a sniper. if you don't see an enemy approaching you, you're almost dead with 70% probability. Un-equipping the wrangler makes your sentry not active for 2-3 seconds, making you an easy target. So be sure to use the wrangler while some of your teammates can protect you or warn you when a sneaky spy is approaching you. This weapon has to be used in a open area where you can shoot enemies (snipers and spies must be your primary targets) and kill them before they can take cover behind a wall. You can use also this weapon to shoot at your feet in order to reach higher spots, as soldiers and demos do with explosive damage. Left Mouse button : shoots bullets . Right Mouse Button : shoots rockets.
The Wrangler is also useful to deal with bonked scouts,spychecking and killing snipers easily.

MvM Pro-Tip (say thanks to X3N1A for this tip) : Put up your Sentry and put down again, so the Sentry is able to shoot immediately. BUT...that only works on MvM...else the Sentry needs AGES to rebuild ;)

Equipping this weapon gives you an additional +25 hp, allowing you to endure more severe damage, although it doesn't allow you to camper anywhere you like. Having with you +25 hp and a mini-sentry forces you to be an active engineer, who loves helping the team with his buildings : you will have to move your dispenser and your sentry very often in order to be a useful engineer. REMEMBER: only snipers and engineers (when playing in Blue defending team) must camper. An engineer with a mini-sentry should never camper, because mini-sentry is suited to hit and run strategies, not to defend the last control point your team had just capped. TIPS : using gunslinger + frontier justice is a good strategy, because when your minisentry is destroyed (even by yourself), you gain critical hits for your primary weapon, making you really dangerous.Moreover, a minisentry costs only 100 units of metal,easily to be found,allowing you to gain later more crits when your sentry is destroyed again. A minisentry has a lower health than a level 3 sentry, so be sure to place it in clever spots so they can’t be easily targeted by sticky bombs, rockets , arrows and whatsoever. Also, don’t place it in blind corners; expert pyros can easily destroy a mini-sentry with circular and precise movements.

If properly used, it can be a real nightmare for all enemy classes: remember that the clip size is reduced and that you won’t shoot random critical hits. When your sentry gun has some kills and assists, destroy your sentry in case you’re not overwhelmed by enemies and rebuild a sentry gun.
Use this weapon in short and middle distance,don't use this weapon to spycheck,use instead your stock pistol.
TIP: having lots of critical hits doesn’t make you invincible and immortal. Think about that.

I love to play MvM with my friends,and i always play at expert difficulty (Carbonado-Diamond).

1 ) ENGINEER IS A KEY CLASS IN MvM
You can't stand still, you always have to think about and how to help your teammates, so you MUST MOVE YOUR BUILDINGS ( so if you're using the Eureka Effect,you're not very clever). Remember also that engi ≠ sniper. DON'T CAMP IN MVM. NEVER.
Before the round starts,you won't consume any metal when building/upgrading your stuff ^^

2 ) MUST - HAVE EQUIPMENT:

Rescue Ranger / Pomson 6000 + Wrangler + Stock Wrench
A R.R. is useful to repair,save and move your buildings and to do the sentry buster trick ( read below) . But be careful while you're moving your buildings,remember that you'll be marked to death for several seconds.
Pomson is useful against camouflaged spies and against robot-medics,because it will deplete their cloak/ubercharge.
TIP: never attack medics,or they will uber themselves. Demo,sniper and spy have to deal with robo-medics.Not you. Never.
Wrangler: useful to long range combat,a great tool to kill enemy snipers/spies and giants robots WITHOUT MEDICS and robo medics that were left without protection.

3 ) WHAT DO I HAVE TO UPGRADE??

An MvM engineer has to upgrade many things: dispenser range ( HAS TO BE MAXED OUT IMMEDIATELY ) , sentry fire speed , sentry maximum health, maximum metal capacity, melee attack speed. After you've maxed these pucheasable upgrades, it's up to you to purchase an additional minisentry upgrade. A mini-sentry is an effective decoy to distractenemy robots from firing to your allies and can also help you to deal with a moltitude of enemies. You can use your sentry gun to block the way in order to stop giant scouts when they're carrying the bomb to your base.

CANTEENS: an engineer has to purchase instant build canteens. This cheap,fast use upgrades allows you to build in a quick instant a good base without spending time and 300+ of metal units. Use them in critical situations.
TIP: if you've upgraded your maximum metal carrying capacity, drop a sentry and a dispenser and press "H" and you'll have a level 3 dispenser and a level 3 sentry in one second. Also if you use a canteen all your buildings will immediately have full heath. Just sayin.

To sum up, these are the upgrades you MUST purchase during MvM:

a) Before the first round starts you have to max out your dispenser range and you have to buy two instant buid canteens.

b) Upgrade sentry fire speed and sentry maximun health

c) Upgrade your maximum metal capacity by ONE point

d) It's up to you,remember what you've read before.

4) WHERE SHOULD I PUT A SENTRY GUN?

If you're noob,feel free to ask to your expert team-mates,they will be glad to help you. Also remeber that your role is to provide a constant health and ammo supply,so make sure your dispenser is well placed. Your sentry gun has to be placed in order to kill those robots who were able to pass through your team fire. A sentry gun has to kill small robots and to slow and weaken giant ones.
TIPS :
- your level 3 sentry gun is not a HEAVY,keep it in mind
- never place a sentry gun in a open space,it will be blown out in a second
- never place a sentry gun neither too close nor too distant from you team-mates(read below)

5) WHERE SHOULD I PUT A DISPENSER?

First,you must have had already maxed out dispenser's range, then you have to put it in a place which is both useful to you in oder to repair it quickly and to heal you team-mates (and get some metal too).

6) WHERE SHOULD I PUT TELEPORTERS?
Teleporters are made for ally Spies,Demomans and Snipers, classes who has to kill robot medics. Ask them where they prefer to be teleported. Also remember to use the right mouse button to place properly a teleporter,so that the exit doesn't face a wall (look at the arrow,while placing the exit).

7) HOW TO DEAL WITH SENTRY BUSTERS (SB) :

Sentry busters at the beginning are quite annoying, but you'll learn quicky how to deal with them.
Before i told you to not build your sentry near your allies, beacuse if the SB explodes near them,it will kill instantly your allies. Do this mistake many times and you'll get easily kicked by your team-mates. Anyway, when a sentry buster approaches,run away with your sentry,when the SB has reached you, it will crouch and it will explode within few seconds,giving you the opportunity to run away, making her blow up without harming you and your team :)
TIP:
A SB does friendly kills! So it means that if explodes near enemy robots,it will kill them.
Pro - Engineers use this trick (also with Rescue Ranger) to destroy robots.
[Flipper,can you use this trick??? Yes,of course]

8) HOW MANY ENGINEERS SHOULD A MVM TEAM HAVE?

Only one.

9)HOW TO DEAL WITH ROBO SPIES:

If they're aren't giant robots on the battlefield,move yourself to a corner so you can't be backstabbed and use your wrangler to kill spies approaching you. Ally heavies can also help you to do spycheck,as well as pyros. If there are giants on the battlefield jump on your dispenser (so you can't be backstabbed) and shoot like a maniac (yes,this time you can act as John Wayne).

10) HOW TO DEAL WITH TANKS:

Take a look to chapter 9 ;)

1) Attacking team

Only one engineer should exist in the team, 3 engineers are useful as a boat in the desert. That engi should immediately build a dispenser near the attacking front and a level 2 sentry / minisentry to protect their allies's back from scouts or pyros. After the first point is capped,try to build teleporters in order to make easier for your allies to reach the front. Teleporters should be properly place in areas hard to be spotted from enemies and in places useful for your allies. For instance,placing a teleport exit near a bottomless pit can be really fun to troll people,but your goal (usually) is to help your team.

2) Defending team

When you defend,try to play multiple times in the same map in order to know precisely where you can find metal supply crates. Always remember to help your fellow engineers to do spycheck,to upgrade buildings and to repair them. While defending, 3 cooperative engineers are a force of nature. Try to place your building in intelligent spots,not near you allie's buildings, with the aim of make enemies's capture harder.
When you defend,first build a sentry,then a dispenser,then a teleporter.

3) Koth maps

Take with you a gunslinger and place a sentry near the cap point,remember to place and ugrade a dispenser near the CP so your team-mates can properly support you. Remember to be smart,fast and to not camper. That's only a suggestion; playing in this way is much more fun than camping in the spawn,isn't it? ;)

Now it's the time for the most common and stupid mistakes you can do in Tf2 while playing engineer.
Here's a SHORT list, i will update it very often :

1) Camping at the spawn with all your stuff while your allies are trying to cap the last point.
Help them. If you want to camp,go outside or play sniper.
2) Builiding near your fellow engineers buildings. it's easy for an enemy demo to destroy everything with few stickies. Place your buildings properly.
3) Help your friends to upgrade their buildings and keep an eye towards enemy spies.
4) Don't be a thief, don't steal metal from your allies,build your own dispenser.
5) Fallen weapons can be used ad metal,walk on them to pick them.
6) If you've managed to do several kills with your sentry, MOVE YOUR SENTRY, the enemies,after you've become famous,will know where your sentry is located and they will attempt in any way to destroy / sap it.
7) As an engineer you can be damaged from you own sentry fire,so be careful. Spies and bonked scouts will try to trap you in order to make your sentry gun killing you. Kill them or use the wrangler to twart their strategy. REMEMBER, YOUR BRAIN IS YOUR BEST ALLY.
8) Take a look at engineer's achievements, they can actually give you useful tips about how to play.
9) Your pistol is useful to spycheck,you've plenty of ammo with you,so shoot until your ears are bleeding.
10) You can jump on your buildings to reach higher spots and you can use your sentry gun (also while using the wrangler) and your dispenser,to protect yourself from bullets and rockets.
11) If you see stickies near your buildings, break them with your shotgun or take away with you your sentry. A sentry can save you from multiple enemies,a dispenser can't.
12)While using the wrangler,you can sentry jump. Just look some videos on youtube to see how it works
13) Remember that you're not a ghost, you can't pass through your own buidings,so you can use them to protect you and as a stair to jump higher. Don't trap yourself into a corner,you'll be an easy prey to spies,pyros and obviously,demomans.
14) Don't take metals from ammo supply crates,engineers need metal to upgrade their buildings,use dispensers!!
15) Place teleporters in clever spots,and remember to destroy the exit if you're thinking that enemies are camping near the tele exit waiting for easy kills. Look below to see an example of a stupid tele exit.
16) If you're near a spawn,remember you can get a full metal supply from your spawn cabinet

1) Scouts-Snipers: really harmful. When you're carrying buildings,you're like a turtle without his carapax. A scout can easily kill you with two shots,so be careful when you want to move up your stuff. The same history for the sniper. You can kill scouts and snipers with your weapons and your Wrangler can help you to shoot from long distance without exposing yourself to enemy fire. Watch out for Bonked scout (see the previous chapter)

2) Pyro: the best ally for an engineer; he can spycheck and remove sappers with Homewrecker and Neon Annihilator. While facing a pyro remember the can reflect to you sentry's missiles and if a pyro comes from an hidden corner,with proper movemements can destroy easily a level 3 sentry gun. So think about that.

3) Heavy+Medic : A troublesome couple,while ubered they can kill you easily. Remenber that your sentry can knock back enemies! A good medic while ubered can act like ashield for his heavy,protecting him from knockback,absorbing sentry's bullets. So you have 3 options:
- Pray your that you team helps you
- Run with/without your buildings
- Shoot the medic while using wrangler,using sentry rockets to send him flying leaving the heavy unprotected

4) Soldier: watch out for the splash damage and to long distance rockets.

5) Demoman : your worst enemy. You'll need luck,skill and help to deal with them. Remember to move your stuff when endangered,to remove stickies and to shoot the demoman,weak to direct combat.
TIP: NEVER MELEE A DEMOMAN,SPECIALLY IF SHIELD-EQUIPPED.
TIP: WHEN YOU'RE PLAYING IN ORANGE MAPS,DON'T CAMPER ON THE TOP OF TOWER,MOVE YOUR STUFF ON AND HELP TO CAP THE FOURTH POINT, or you'll see infinite suicide demomens flying towards you and your buildings.

6) Spy: Your main antagonist,avoid close combat, a good spy can trickstab you easily and sap all you've previously built. Use your shotgun at close range, and your pistol. Use the wrench only when the spy is not facing you. If the Spy had sapped something,revove the sapper from your sentry,so it can give you cover. Another good thing against spies is to pay attention to the battlefield and to do spycheck. Also positioning buildings in a proper way is a good thing to do (look previous chapter).

As a Scout : protect your engi when he's moving his things up and warn him when enemies are approaching. If you think that your fellow engi is quite noob,feel free to spam the X4-X5 and X6 voice command, eventually you can be really helpful to him (and annoying,of course ^^)

As a Pyro : do spycheck, remove sappers with Neon Annihilator / Homewrecker and airblast ubered classes,rockets and stickies.

As a Soldier : keep the spam level high and NEVER TAKE AMMO CRATES,these are for your engies. Use a dispenser.

As a Demo : you're a defence class, able to spam and to keep control of huge areas with your stickies. Remember also that as a demo you've a significant advantage in comparison to a soldier: you aren't forced to shoot only directly to your enemies, you can take advantage of walls and bouncing bombs, things that a soldier doesn't have.

As a Medic : Give a continue flow of overheal to you engi when he's carrying his stuff forward and uber him when he's repairing a sentry while he's under enemy fire (you'll get an achievement for that) . You can also uber yourself to stop enemies. Also, the Medic is really effective against spies; remember that the medic is the second best melee class so....use that ubersaw!

As a Sniper : use your jarate on spies and kill enemy snipers before they can aim you your engi.

As a Spy : stabbing people and enemy spies is really helpful.

As a Heavy : you can give to your Engi a sandvich when he's on fire and you can shoot infinite bullets when you're near a dispenser. But remember to move,you're not a level 3 sentry gun ^^
As a Heavy,you're maybe the best bodyguard for an Engineer,think about that (Take a look to Heavy's achievements...just sayin...).
TIP: When your engi is moving his things forward,protect him from pyros,spies and snipers. Snipers? Simple. Equip the steel fists and walk, shielding your engi. You've got 300 hp and bullet resistance while you have them equipped, your fellow engi hasn't.

1) The Widomaker

This weapon uses your metal as ammo each shot fired will consume 30 metal, making for a maximum of 6 shots,you don't need to reload. Each point of damage done to an enemy player or building as metal; as such, the amount of metal returned can be greater than the amount expended when fired if enough damage is dealt. This weapon is great when you can deal for sure massive damage,however,it's the worst weapon to use to do spycheck. You'd better use your stock pistol do that.

2) The Pomson 6000

The weapon fires an unreflectable projectile beam that doesn't consume ammo. Anyway it has to be reloaded. When you hit an enemy Medic he will lose 10% of his ÜberCharge, while a Spy will lose 20% of his Cloak (Cloak is drained after damage is dealt, so Dead Ringer Spies can still feign death to a Pomson shot).
This weapon is perfect to spam and to do long distance kills usually non available for the engineer.
Also useful in mvm against giant Medics.
However this weapons suffers from a slow fire speed. I highly recommend this weapon, but you'll need a lot of practice to be able to use it properly.

3)The rescue Ranger (RR)

While the Rescue Ranger is the Engineer's active weapon, it is able to pick up any of his buildings that are in his direct line of sight from long range, at the cost of 130 Metal. Hauling a building in this way will immediately teleport the building into your hands. When you're carrying buildings you'll be marked for death for few seconds. The weapon also fires unique bolts instead of bullets, which can repair friendly buildings that they are fired at with no Metal cost.
TIP: It's the best weapon when you're doing Mvm (see MvM chapter).
TIP: You can't remove sappers firing with the RR,you still ned your wrench and you won't be able to repair teleporters with RR's bolts
TIP: NEVER USE THIS WEAPON WITH EUREKA EFFECT(EE),YOU WILL ALWAYS BE NOT CAPABLE TO MOVE YOUR STUFF, while the EE is equipped.

4) Short Circuit

This weapon fires a burst of electrical energy that destroys enemy projectiles and stickies,making it very effective to protect your buildings. This weapons consumes you metal supply,so be careful,you'll have to do spycheck with your primary weapon instead.

5) The Southern Hospitality

Melee weapon for the Engineer. When you hit an enemy with this you'll made them bleed for five seconds. As a downside, this weapon does not deal random critical hits, and while wielding it you'll have a 20% fire vulnerability. So, be careful against pyros and use your wrench against spies,you will detect them even if they cloaked ^^

6)The Jag
Melee weapon for the Engineer. This weapon speeds up the construction of any building, whether on initial setup or redeployment, when you keep hitting your buildings. As a downside, the weapon also has a 25% damage reduction, making this wrench less suitable against Spies,forcing you to use alternative weapons to deal with them. This weapons is designed to re-build a broken base you've made in a shorter time,not else. I don't recommend that for MvM, you actually need to do melee damage to spies and Tanks(sometimes).

7) The Eureka Effect
Melee weapon for the Engineer. You can't move your stuff with this weapons, pressing alt-fire or taunting (default key 'G') will cause the Engineer to perform a taunt for approximately 2 seconds and you be teleported to your spawn,with full ammo,health and metal.
This weapon in my opinion it useful only when enemies are near at your spawn or when you're defending in payload maps. In any other cases,this weapon is useful as a punch in your stomach while you're eating.

Lesson Number One : keep an eye to distances!!
Look at this (crappy) image. Some enemies are taking cover behind a wall(red dots). You sentry gun ,if well placed can kill them quite easily. However, a sentry gun isn't a sniper so it can't shoot from here to Mars. Instead, an enemy sniper could! So, while your enemies are waiting, their fellow sniper is damaging your sentry with ease. What you can do : use your wrangler to kill the enemy sniper (if he's not properly hidden) or move your sentry, trying to don't get headshotted in the meanwhile.

Lesson number Two : pay attention to corners and how to use them properly
If you put a sentry in that little corner, an experienced pyro can easily destroy it with that circular movement ( red line). You should put your sentry in the left corner to avoid that stupid placing mistake.

Lesson number three: don't trap yourself !! NEVER!!!
You should never trap or got yourself cornered by yours buildings! You're not a ghost ( O RLY??) so you can't go through them. If you'll find yourself in a such situation,you'll be dead as soon your enemies will spot you. You can't stay in too open and isolated areas but you can't either hide yourself like Jerry when he's chased by Tom,the cat.

Lesson Number four: How to deal with Tanks
Above you can see the typical situation that often occurs in MvM. Your dispenser should always placed with the purpose to support your teammates,not you. Your senty gun has to kill little robots and to weaken the tank. Be careful to not being hit by your sentry gun. You have also to move your gear, following the tank path and if possible to hit the tank with your wrench. Pay attentions to robo enemies coming behind the tank.

Lesson Number five: how to deal with Sentry Busters (SB)
At your left (image 1) you can see the most occurent situation. Your allies (red dots) are shooting enemy robots using your FULLY UPGRADED LEVEL 3 Dispenser ("repetita iuvant" guys,check on google the meaning of this Latin sentence) while a sentry buster is approaching. A SB will go immediately towards your sentry gun,so move your sentry and go back with it, in order not to endanger you allies.

TIP: a dispenser should be always be placed behind a sturdy wall,so the SB will not be able to walk on it,destroying it in the meanwhile.





Now (image 2) when the SB has reached you (point A) ,it will crouch and it will explode in few seconds,while the SB is doing this movement,just run with your sentry to point B and you and your allies will ben safe.

TIP : A SB will chase you even when you have you sentry gun with you,so let her chase you where you want; remember also that when a SB crouches,it will be no longer able to run to you.

To take care of spies you always have to keep in your mind these 4 simple rules :
1) Even if no one seems approaching you and/ot your buidings, keep on SPYCHECKING at 360° with your pistol and your pomson 6000.
2) KNOW YOUR SURROUNDINGS : if for any reason you are near defeat, try to find an escape route in order to save yourself and one of your buildings from destruction. The best thing to do would be figuring out an escape route BEFORE defeat.
3) Try to THINK AS AN ENEMY SPY : Where are the easiest buidings to sabotate ? Which corners and areas can i use to hide myself ? When will it be the best moment to kill the enemy engineer and to sabotate all his stuff ?
4) You are a modern engineer, and not a prehistoric man equipped with a wooden club so, if a spy is approaching, FIRST use your shotgun/pistol and then your melee weapon. Attacking only with melee weapon exposes you to trickstabs and enemy fire. Remember that an engineer is not a Heavy, you have only 125/150 hp (repetita iuvant).

Now let's take a look to some basics strategies explained with very simple (sorry,i'll be an artist in the next life) images.

1) How to properly destroy sappers :
You can see a typical situation. Fist thing to do : un-sap the sentry gun from point B. If you do that while you're in point A, you'll be backstabbed and your buildings will be doomed. When facing a spy,rembember to un-sap the sentry first; it can provide you help and protection. Also, lots of noob spies will often try to shoot you or stab you, unequipping their cloak ; that will make them an easy target for your teammates and your sentry gun too. So,to sum up, in these circumstances keep and eye to two things : your sentry gun and the enemy spy's position.







2) Things that you should NEVER do against a spy :

When you're running towards an enemy spy, be careful to long and stretched corridors ; an experienced spy could easily run away from you or kill you with few shots. If you're chasing someone, be sure also to have some movement freedom; as said before.... DON'T TRAP YOURSELF. Oh,another thing : if you're chasing someone, use your pistol ! You should not running around swinging your wrench like a raging monkey; your wrench is useful in close ranged fights. It's not designed to cover great distances.










Here's another situation: if a spy has just disappeared behind a corner, he's likely to corner-stab you. To avoid that, follow the red route i wrote below:
The spy ( blue fat dot ) will try to do that blue movement ; follow the red route and press your back to the wall,in order to don't get backstabbed and use your shotgun to kill the enemy spy.

Working in progress,images and commnents incoming ;)