The Frontier Justice: Possibly one of the most useful guns to ever grace TF2. The gun is useful because of it's literal killer-of-a-feature: Gain guarenteed "revenge crits" for every sentry kill and assist kill done with your sentry (1 for an assist, 2 for a kill). As soon as said sentry is destroyed, you gain those crits, with the tradeoff of a 50% smaller clip-size and no random crits, and LOSING the crits on death. This'll be important later.
However, as this video shows, there's alot of spy-checking and Frontier Justice behaviour that needs to be addressed...
1. Engineers, and budding Engie Mains
Do NOT, and I cannot stress this enough, DO NOT pair the Frontier Justice with your regular sentry gun. It initially sounds like a good idea, as Level 3 sentries generally kill more people, so it's assumed that you'd gain more revenge crits. And you do! But take it from me, It's not worth it.
The reason is because your life matters...trying to stay alive for as long as possible, that is. A longer life for an engineer makes a spies life harder to gain an entrypoint into your sentry nest, sap the sentry. and leave without ever being noticed. The idea behind the Level 3 sentry is to rack up kills, and keep it well-maintained. When you feel like it, you can go on a killing spree with your weapon of choice (preferably the stock shotgun, as it has a bigger clip size than any other weapon Engineer has). You'll soon realise that going around killing (or the trying thereof) with the Frontier Justice is harder than it appears on paper, even with "revenge crits".
Because of the 50% smaller clip-size, you have to reload more, and in the middle of a sometimes literal firefight, reloading needs to be kept to a minimum, and no amount of a crit-ting chance will help with that. You'll soon realise this halfway through trying to take down a non-pop'd Heavy/ Medic Combo, when you suddenly turn into dead meat. And once you're dead, you lose those well-earned revenge crits. If you're playing to mainly defend, equip the Rescue Ranger or, again, the standard Shotgun as those will be far more useful than the Frontier Justice!
Basically, there IS such a thing as too many crits, and just because you have crits, doesn't mean you're invincible. As such, The Frontier Justice is much more useful as an offensive Battle-Engie weapon (The Gunslinger, which grants the mini-sentry, The Frontier Justice, and the Pistol/ Wrangler) as it allows you to forego the responsibility of maintaining your buildings and be as wreckless as your heart desires. Though it's a good idea to place a dispenser somewhere for yourself and the team to use. And Teleporters since the MyM update made them 50 metal.
2. Spies: In case it wasn't obvious...
Avoid disguising as the person you're trying to kill, because any seasoned engineer with a hat, even a gibus, will be able to spot you and easily hunt you down unless you're very quick to get the hell outta there. Especially if their hats/ cosmetics in their loadout are painted bright colours, like Pink as Hell, Mann Co. Orange and yep, even Aussie-um Gold (like mine).
Also, Don't just sap the buildings and forget about the engineer. Like I mentioned above, getting rid of the engineer is imperative in most cases, with the only real exceptions being most CTF maps, and pushing the payload when it's directly (and I mean directly) near a checkpoint. Get rid of his Sentry, (Attempt to) to backstab him, re-disguise as any class bar Scout and that Engie-you-just-killed, and go and enjoy a beer on the crowning achievement of playing Spah properly!
3. While briefly touched upon in the video, Some Classes are better to deal with Spies than others!
A Heavy/ Medic combo is not ideal, but they are useful at pinpointing the spies general position, thanks to the cloaking device being defeated as soon a Spy is hit. The Pyro is obviously the best class to hire for Spah Detection Services, as Fire is lethal to a Spy. Even a Sniper equipped with the The Tribalman's Shiv (which makes enemies you hit bleed for 8 seconds) is better than most other classes at this task, sometimes BETTER than a Pyro in certain situations.
This was made for the TF2 72 Hour Summer Jam 2016, and it's my take on the series made by Krunkidle -Team Service Announcement, with a similar OTT formula. The creation process was (mostly) streamed Live on Twitch, and uploaded to a playlist here: https://www.youtube.com/playlist?list=PLKLo9n_NACm7w3XaM8ScR8C6u-MmVN2vm. Overall, the video took less than 10 hours to create, and used a mixture of Animation Sequences, Manual Posing and various particle effects.
Music Used: MEDIC!
Various Sound Effects found in TF2.
Oh, and LEARN.