Hey look buddy, I'm an Engineer; that means I solve problems.
Not problems like 'What is beauty?', because that would fall within the purview of your conundrums of philosophy. I solve practical   problems. Today, I will grant you a look in my duties on the battlefield.

Beforehand, few information about myself: I am quite small, relatively weak and rather poorly armed. In an open fight, I surely would end up as cannon fodder for the frontlines. My abilities focus on the support and the defense. Often, I decide over victory or defeat with my constructions. That is my appeal: building and maintaining constructions.

Before we start with the actual building, we need to clarify some substantial questions:

• What should be build?
• Do I have sufficient metal for that?
• Where should I build?
• Is it safe there?
• Does it help my team?

These are the very questions, every Engineer ought to have in mind, before he takes is tools because an Enginner without a plan is as helpful to his team as a Pyro without flamethrower.

Speaking of tools, let's have a look at my equipment.

Equipment

The Wrench

The Wrench, in any realization is one of the most important tools - besides the PDA. It quickens the construction of buildings, it upgrades them, it repairs them and it removes the Electro Sappers. Speaking of Spies: If one of them dares coming near my constructions, I even can punch with the Wrench.

The PDA

With the PDA, I have the ability of choosing bulding maps, thus building them. On the other hand I use the PDA to destroy them with a special mode. Moreover, the PDA provides me with all necessary information about my buildings, e.g. level, progress and condition. Of course, the PDA was developed by Texas Instruments.

The Shotgun

My baby! With the shotgun, I defend my constructions, that can't defend themselves. At close range it is pretty powerful and deals a lot of damage. In contrast, for longer distance I rather use my Pistol...or the Sentry.

The Pistol

I guess I do not need to explain what's the essence and usage of a pistol. However, every Texan Cowboy should have one.

The Wrangler

The Wrangler gives me the oppurtunity of having full controll over my Sentry Gun. With the Wrangler equipped, the Sentry switches in a manual mode and stops aiming at enemies automatically. Now, we have to aim and shoot. Simultaneously the Sentry is provided wit a additional shield, which absorbs 66% of the incoming damage. With the left mouse button, we shoot with doubled speed, the right one shoots rockets if we have upgraded the Sentry to level 3. The Wrangler is indeed a good choice when the Sentry Gun is constructed rather openly and thus easily attacked by enemies that are outside the automatic range. Though one should pay attention that with the doubled shot frequency, the Sentry has an increased usage of ammunition. Therefore you should hit it with your Wrench quite often. If you chose the Wrangler, you will have no pistol. So think about wether the Wrangler is useful to you or not before the round starts.

The Gunslinger

With this Cyborg-Hand, I become a front-line soldier. It prpvides me with 25 additional HP and a Combat Mini-Sentry, that is constructed more quickly and cheaper. In contrast it is neither upgradable nor can it be repaired. I should only chose the gunslinger when I want to fight at the front-line. For support or defense, this item is rather useless.D

Well, now you know about my tools and weapons. There are a couple of alternatives for some of the mentioned weapons. However, they are quite similar to the ones above. A list of the alternatives can be found  here.

Constructing

Let's attend to the constructions. If I want to build one, I'll have to choose a building map from the PDA and put it on an even area. A red cross on the map means, that I can't build on that place.

Rotating

Before I eventually start my constructing with the click on the left mouse button, I should face the construction properly. This can be done with the right mouse button. The arrow shows the direction the construction will face. This is essential for teleporter exits, since a wrong faced exit will let my teamates run agauns a wall. And that means a loss of precious time.

Upgrades

After the constructions are placed, they are upgradable via hitting them with the Wrench. Make sure that you have enough metal for the upgrade. If not you should pick up ammunition boxes, dropped weapons or use your dispenser. The display for metal is in the bottom area of your screen. It is the little box with the jaw spanner symbol.

Maintaining

Naturally, the buildings need maintaining. If a constructions is damaged, you will get notified on you HUD. Hit the building with the Wrench to repait it(don't try this at home). A Sentry Gun requires ammunition. With no mire ammo, the Sentry is useless. Even here, it is enough to hit the Sentry with you Wrench to refill the ammo. Enemy Spies will surely try to disable you buildings with the Electro Sappers. You remove them with a hit from the Wrench as well. In contrast to the upgrading, repairing and refilling, this needs no metal.

Replacement

 If you want to have a construction at another point, you don't have to demolish it and then build a new one. With the right mouse button you can simply pick them up and replace them. While you carry the buildings across the battlefield you move more slowly and more important you are completely without defense. Though, if you reach your destination without dying, you can put down your construction fully upgraded. This saves time and metal in contrast to the Demolish-and-rebuild method. Though, carrying a teleporter entrance to the next spawn point is not economical. You save more time with rebuilding it at the new spawn.

Constructions

Now you know everything about my equipment and how to build, but none at all about the actual buildings. That's coming now. These are the constructions you may build:

The Sentry Gun

The Sentry Gun makes me as Engineer  a really serious Texan. A well placed and maintained Sentry was the deciding point in a lot of matches. In fact, it is a spring gun equipped with machine guns and even rockets on level 3, that aims and fires automatically at enemies in a specific range. The verry construction costs 120 metal, the upgrade to the next level even 200. With every level, the life points of every building are increased. Moreover, the Sentry gains more firing power. On level 1, it could be destroyed by a scout, but on level 3 you definitely need a ubered Heavy-Medic Team to put it down. In any other cases all enemies will be transformed instantly into a huge chili. Furthermore, a spy can destroy a Sentry with his Sappers, but a good Demoman is possible to blow up the Sentry with Engineer - just with a few well placed Sticky Bombs. Therefore, the place of the Sentry should be choosen well. The Dispenser should be quite near, since the maintining of the Sentry costs metal. With the Wrangler, you can simply remote control the Sentry.

The Dispenser

The Dispenser stands on the battlefield and provides hurt teammates with life energy like a cactus provides water for a thirsty cowboy in the Texan desert. The Dispenser is a good substitution for a Medic as well as source for ammunition. Players, that refill at your Dispenser provide it with metal. So you don't have to look around for dropped weapons all the time. Place your Dispenser where it's needed: the front line. However, that doesn't mean that you can simply put it on the field. Search for a secure place that is easy accessible for your team mates near the actual fight. When you focus more on the support, place it in the area around your sentry, so that you have short ways to refill your metal. Plus, don't forget to upgrade your Dispenser! A level 3 Dispenser gives metal, ammunition and health more quickly than a level 1 Dispenser.

The Teleporter

Teleporters are vital for your team! They, bring the attack classes faster to the front line than a Texan bull a rider from his back. Imagine you live in story 55 in a skyscraper ant there is no elevator. That's exactly the feeling of a Heavy that has to run from the spawn to the next control point or the lory. So place your Teleporter Entry at the spawn and the Exit near the fight, but please a safe place. Don't forget to upgrade your Teleporter! A level 3 Teleporter requires the same time for 5 teammates as a level 1 Teleporter for 1 teammate. A stable connection between spawn and frontline is essential for a victory, since this means no breaks for your enemies! Though look out for spies! They love sapping your Teleporters!

I really hope the guide could give a good view on my work. I hope it clarified that I am not a useless class - if played properly. Now that you know everything, take your Wrench and go to the battlefield to support you team and defend the control point, because that is what I am: a supporter and a defender!

Your Engineer from Texas