We Engineers have a problem in terms of killing power. Our health and armour is very low compared to the majority of attackers, and although we may be faster than most, we're still prone to easy gibbage.

With this in mind, we need to kill our attackers before they get a chance to kill us. If we are deep in our base we can be pretty sure that any attackers will have chunks taken out of them before they reach us, so our Railgun or Super Shotgun is an ideal choice - as long as the attacker is surprised. Most of the time, though, this isn't the case. This is why all engineers must become experts with their grenades.

• You'll be on ramp defense, and the demoman you've been working with has just chosen that precise moment to go get more grenades (hey buddy, what's wrong with asking ME, eh?) when a soldier appears below you. Prime an EMP grenade then drop down and chase the sucker. Throw it in his face after two and a bit seconds, and he's toast.
• Hopefully that scout who deceided to dance with you didn't discard before leaving his base, so he has some rockets, too. Chuck an EMP at his feet. BOOM.
• How about discarding yourself? Load up on rockets then discard into the centre of the Ramp Room - then when some poor sucker comes running for it, an EMP close by will blow the backpack and the sucker. If they manage to pick it up, the EMP will blow them.
• Just about to die, or overrun with enemies? Throw all your grenades in the direction of the enemy - one sure way of taking at least one bad dude out.
• You know he's a spy, but he doesn't know you know. Prime a normal grenade and go behind him. He'll think you're running for supplies, and he'll sidle towards your gun - so turn and launch that pineapple at his back (mind your gun!).
• The enemy has the flag and you're the only one left? Prime a grenade and keep that key pressed, then run directly behind the dude - you'll explode, he'll explode, but it'll give your guys a chance to regroup and protect the flag - remember, you can't take people out that easily, and in TF suicide is painless...

Don't underestimate your grenades. The EMP is one of the most powerful weapons in the game. Make sure you stock up on rockets from your dispenser before sweeping a resupply area for grenades, and remember where the grenade restocking locations are in certain maps (rock1, chaos1, etc.).

Sentry placement is a tricky thing - most engineers know the best locations for guns - and so do most offensive squads. This can cause problems when you're defending against TEAMS of attackers. If this happens, you MUST team up with another defender, or if you're in a major choke point, two other defenders. Your Sentry Gun will be destroyed almost instantly if you do not do this. It is possible even on public servers, just make sure you give your cow-orkers (ORK ORK) some ammo and armour, and they'll stick by your gun for the duration.

If you build your gun away from the wall and you see a nail grenade, just run behind your gun, then continually repair it - you don't die 'cos the gun takes the nails, and the soldier thinks your gun is WAY low on health so he comes charging in and fires one rocket them BOOM he's sentry-mincemeat.

Actually, soldier killing is easy. You just bait them - float around the entrance corridors and fake them out. I love doing this. Stand in the dark with a super shotgun in one hand, catch their attention with a few well places shots to the head, then go running - right to your gun. BOOM.

Did you know that when building a gun underwater, you can hold down the "jump" key and float to the surface for air? Demomen can also do this when detpaking under water...

Some spies are stupid. They hang around your gun too much, or wave their axe about. Don't let them realise you know they're spies until you're in a position to waste them - firstly, let your team know there's a spy around and what his skin is, in case you don't get him. Then, prime a grenade and throw it in his face, followed up by super shotgun blasts to his head. He'll go down. If you're NOT sure he's a spy, do the "run at him with your spanner" trick. Does he run for cover? Shoot just to make sure...

Is that a dead body breakdancin' in the corner? I love to find spies feigning death. You just stand on their heads. "You can't stand up with someone on top of you" the spy is told. *BANG* *BANG* *BANG* goes my railgun. Then the body stops moving, very satisfying.

Care for your fellow team mates - don't just think of your gun (I know it's hard). Make sure you restock armour of anyone who is defending, and on maps that don't give full armour for hwguys and soldiers make SURE you stock them up, especially before they assault the enemy fortress.

Discard often, especially if a soldier, demoman or pyro is on defense - they need rockets to make them feel safe, kinda like Sentry Guns to engineers... If you can, discard AT them, so they don't need to leave their post or turn at all. Often they will turn to see what just happened, and then stay facing you to type "Thanks eng" - which is when the enemy assault will begin. You can almost put money on it.

Don't forget DROPAMMO - engineers can CREATE other ammo types out of cells, which is very useful - drop boxes of shells on the sniper nest, throw a few rocket packs in a resupply room, but make sure the enemy doesn't pick them up.

If you can pair up with a HWGuy in a Ramp Room, you've got it made - it's like having two Sentry Guns to look after. Very satisfying.

It may be hilarious to build a gun in an enemy base, but it is NOT productive. I've done it before myself. Ready for a bed time story?

One time long ago I was playing on a server with six players per side. It was 2fort4 (for a change, h00 h00) and our side was doing rather well. So well in fact that I was getting bored of just holding the Ramp Room. I wanted some FUN!

I rushed out of my base, waving at our sniper (who was doing a LOT of supression work) and ran across the bridge. In the exact centre of the outside of their fort I built a sentry gun. It was facing towards our fort. I slapped a dispenser on the other side of one of the enemy ramps and proceeded to upgrade the gun to level three.

I then sat there, EMPing anyone who got too close, and giggling as the enemy would jump screaming from their Sniper Nest - only to get a rocket in the back. Some would come from the main entrances - and the same would happen. When the enemy realised (and it took them a LONG time), they tried to get my gun - but I managed to keep it going for quite some time.

When it was blown, I set a new gun outside their upper respawn room. I got it to level three, and my dispenser was by their spiral - I blew up quite a few basement respawners who were trying to surprise my gun. They were trapped!

Then it hit me. Where's the challenge? They couldn't organise a proper defense for our offense to bust wide open. There were no enemies trying to sneak into the ramp room to plant a detpak, no frantic rushes to the Spiral when they got their grubby paws on our flag, no "Incoming - water!", nothing.

Putting a Sentry Gun into the enemy base when they had very few team members to start with had totally locked them down. It wan't FUN anymore. I imagined how they must have been feeling - I bet they all HATED me for doing that, not the normal kind of "damn you and your sentry gun, I know where it is now, we'll get it next time!" kind of reaction, but a real physical "I want your head on a plate" feeling. I didn't feel good about myself. I had ruined the game for myself and for everyone else. My team came top, but I felt SO low.

I'll never do that again.

There's no tactical advantage in placing a gun in the enemy base - Sentry Guns are supposed to be an integral part of a team's defensive armament. The goal of MOST maps is to take the enemy flag to your touchdown point - it is not about who kills the most people, or which side traps the enemy in their fortress (fullteamscore ON!). As an engineer, your gun is there to stop or slow down attackers who are intent on getting your flag up and out of your base. If you place your gun in any other manner, you're playing Death Match, not Team Fortress.

I've discussed this with a lot of people, and there are quite a few who think "anything goes as long as you win" - where is their honour? If that's how they carry themselves on a field of battle, I don't want to play with them. They're not promoting TF at all, instead they're detracting from it - people who are trapped in their resupply rooms because of an enemy sentry gun outside, or repeated napalm attacks, or nail grenades thrown by the door again and again, will soon stop playing Team Fortress. Think, learn, and beat your enemy in a different way.