Mann vs Machine is Team Fortress 2's robot-slaying, wave-based, co-op game-mode. Though both TF2 and the MvM mode are free, those looking for a little extra challenge can buy tickets to access its advanced difficulty Mann Up missions. Designed for skilled players and well-coordinated teams, Mann Up's toughest tour of duty is Operation Gear Grinder - sure to test the mettle of the most hardened bot-bashing TF2 crews. It's hard. Very hard. In this guide I'm going to take you through some tips for dealing with each of Gear Grinder's missions, suggest team set-ups and lay out the loadouts you should be using if you want a chance at snagging the operation's ultimate reward: a diamond botkiller weapon.
One of the beauties of Mann vs Machine in the past has been that there aren't any essential classes. There may be recommended classes such as Scout or Engineer, but in advanced difficulty missions it is possible to get by without them. In your first expert tour there's less room for manoeuvre, but here are some suggestions as to what loadout you should use for whatever class you choose to play as well as some advice on your role:
Scout: Scattergun, Mad Milk, Fan O'War
Money is important in all Mann vs Machine missions, but it's extra important in expert mode. First and foremost, your job as a Scout is to get as much money as possible, because you'll all need as many upgrades and canteens as you can get.
The Scattergun is a very capable weapon, with six rounds per clip and its meaty damage at close range. It's easy to make it even better too, if you upgrade the reload speed and clip size. The Force-A-Nature is a good alternative if you can upgrade the clip size due to the gun's inherent knockback effect, handy for pushing the bomb carrier back in the absence of a Pyro's airblast. You may even consider the Soda Popper for consistent bursts of mini-crits.
The Mad Milk is a certainty for your secondary slot, make sure you upgrade it to slow down targets and apply it liberally to giant robots. This allows all your team mates to heal from dealing damage to them.
The Fan O'War is a weapon that's rarely used in regular TF2, but is a very solid option in Mann vs Machine. It doesn't need to be upgraded, just hit giant robots once and they'll be subject to mini-crits, which are worth their weight in gold. The Sandman is another option in the melee slot, but it needs to be upgraded before it can mark targets for mini-crits and given that money's tight in expert mode, you may not be able to afford it.
Upgrades: The Mad Milk slowdown effect is cheap and essential, focusing on building up your resistances is imperative too. If you've got cash to spend on your weapons, focus on your primary weapon's reload speed and clip size.
Soldier: Rocket Launcher, Buff Banner, Escape Plan
Soldiers are an excellent class to use during expert missions. There is some debate as to whether the standard Rocket Launcher should be used or the Beggar's Bazooka, but the Rocket Launcher 's been recommended for those situations where you'll need to take out targets at long range (especially Snipers) and can't rely on the Bazooka's unpredictable accuracy.
The beauty of using the Buff Banner is that it will recharge extremely quickly even with just slight upgrades to your primary weapon, and the damage bonus it provides for your team is essential for dealing with tanks and giant robots when they attack together. It's also very cheap to fully upgrade.
The Escape Plan is the selfish option for your melee slot, but you will need the extra speed to get away from difficult situations. The only practical alternative is the Disciplinary Action, but its unreliable hit detection and dependence on having a friendly player near you to benefit from its boost makes it a poor choice for emergencies.
Upgrades: Focus on your primary weapon, specifically reload speed, clip size, firing speed and ammo capacity. You can fully upgrade your Buff Banner for just 500 credits, although this isn't as important as upgrading your weapon.
Pyro: Flamethrower, Flare Gun, Axtinguisher
A Pyro's job in any expert mission is very important because of their airblast. Every Mann vs Machine map has at least one place for you to knock the bomb carrying robot into that will delay its journey to the hatch or, in the case of Coaltown, reset it completely. With that in mind, the Backburner (expensive airblast) and the Phlogistinator (no airblast at all) are terrible choices for expert mode. The standard Flamethrower 's been picked over the Degreaser because of its superior damage and you'll very rarely be in a position where you need the rapid weapon swapping that the Degreaser provides.
The Flare Gun 's the best choice of a bad bunch of secondaries, use it to crit big robots from long distance. The Scorch Shot may seem to be an attractive alternative, but its knockback doesn't pack enough punch to reliably push bomb carriers back or down pits.
Finally, the Axtinguisher just about edges the Neon Annihilator as the best melee weapon because you're in control of whether your target's on fire or not, whereas the Neon Annihilator's critting of wet targets is down to your team. However, the Annihilator's ability to remove sappers in the absence of an Engineer can be very handy, even if it is a little bit situational.
Upgrades: Airblast force is a very important upgrade, but how much you should spend on it varies from map to map. On Mannworks you should feel free to spend all four points on it because there's a very large hole that you can easily knock the bomb carrier into from very long distances. On Coaltown you're better off only spending a couple of points otherwise pushing small robots down either pit can be more trouble than it's worth. Finally, on Decoy, three or four points will suffice because there will be plenty of times where a giant robot will have the bomb on either bridge and you'll need to airblast them off, requiring a lot of force. Otherwise, focus on resistances and ammo capacity. If you have spare credits after that, you can start upgrading primary weapon damage as well as melee attack speed if you're using an Axtinguisher.
Demoman: Loch-n-Load, Scottish Resistance, Half-Zatoichi
Demomen can deal enormous spikes of damage with several carefully placed sticky bombs, and are very useful for taking out Uber Medics before they have a chance to Uber their targets. The extra damage provided by the Loch-n-Load edges it above the regular Grenade Launcher, although you will need to upgrade its clip size and reload speed for it to be competitive later on.
The focus of your upgrades should be spent on your secondary weapon. In this case, the Scottish Resistance has been chosen thanks to the six extra bombs you can have out, up to a maximum of 14, and the fact that you can selectively detonate them. Lay some stickies at each entrance point, particularly when anticipating Medic bots, and detonate as soon as they're in range. This does require some team coordination though, as Uber Medics are quick to deploy their Uber at the first sign of damage, so the rest of the team will need to make sure your bombs are the only things that touch them.
The Half-Zatoichi is a very situational weapon, but it will heal you to full health if you can kill a bot with it. Just be very careful not to accidentally switch to it in a panic, otherwise you're stuck with it until you can kill something with it and your group will suffer from the lack of damage. If you're not confident in keeping your sword sheathed, then the regular Demoman's Bottle will suffice.
Upgrades: Concentrate on upgrading the Scottish Resistance's firing and reload speeds as well as ammo capacity. If you can spare 500 credits, even one point spent in upgrading damage is a point well spent. Upgrading your Loch-n-Load's reload speed and clip size is very worthwhile too. If you can't afford to upgrade the Loch-n-Load, then using the standard Grenade Launcher is a good option because it will perform slightly better with fewer upgrades.
Hit the next page for loadout lowdowns on the Heavy, Engineer, Medic, Sniper and Spy.