Set in the ruins of Washington D.C. during the zombie apocalypse, the game follows a group of survivors known as the Camp, who come into conflict with a larger, much more violent and thuggish group of survivors known as the Family. The Camp's four primary troubleshooters are Heather the Scout, the Camp's co-founder who favors a crossbow; Aidan the Tank, a shotgun-wielding brawler; Grant the Tactician, a Cool Old Guy survivalist sniper; and Maya the Support, an SMG-wielding medic.
The game has a character upgrade system and mission structure heavily influenced by OVERKILL's previous game, PAYDAY 2, with players being heavily encouraged to replay missions over and over again at increasing difficulty to earn weapons, experience, and resources. Additionally, a base management system is present in which players recruit NPC survivors and upgrade their base's facilities to upgrade their character's capabilities, while at the same time having to maintain resource levels by completing missions to keep the base stocked with supplies.
Unlike previous OVERKILL games, there are no partner bots for single-player mode, nor is there a dedicated single-player mode feature at all. You can play the game without any co-op partners, but the game will be significantly harder than intended.
Like PAYDAY 2, OVERKILL planned for The Walking Dead to be continually updated with new missions and content as time progresses. The initial release of the included Season 1 of the campaign and Season 2 was scheduled to be released throughout 2019, however the license holder, Skybound Entertainment, terminated their deal with Starbreeze in February 2019 after disappointing critical and commercial reception and had the game removed from Steam, killing any chances of Season 2 releasing in its entirety.
The game provides examples of the following tropes:
- A.K.A.-47: Used extensively, for example Colt firearms such as the M1911 pistol or M4 carbine are referred to as "Corvo" firearms i.e. Corvo 1150 pistol or Corvo CAR-4 carbine.
- Anyone Can Die/Decoy Protagonist: Heather, the default player character and the one most central to the plot, is killed halfway through the game by Hurst, the local leader of the Brigade. Her role in the team is taken over by Reina, the leader of the Family, who joins the Camp in an Enemy Mine to fight the Brigade.
- Artificial Brilliance: Although the game was heavily criticized for poor human enemy A.I., the A.I. actually does quite a lot of impressive actions, such as repositioning when you take cover, actively flanking from cover to cover, ducking or sliding sideways when shot at, moving to your flank but then staying behind cover to put pressure on you while their buddies move in instead of popping out of cover while you're aiming at them and exposing themselves, using grenades to flush you out of cover, or hanging back and providing overwatch/covering fire when other teammates charge in. On the whole, while the A.I. might be average by AAA FPS standards, the game's combat being extremely punishing due to scarce ammo and health and the noise meter makes it so that human enemies can be very effective at ruining your chances of success simply by being basically competent.
- Artificial Stupidity: That being said, the human A.I. is prone to some dumb moves, such as clustering together in groups that make them prime molatov fodder, or charging around a corner one after the other even as you mow each one down that does that. The A.I. behaves the dumbest in the wave-based defense missions, which are primarily where people who only play the game for a few hours will face them, which leaves a very negative first impression.
- Armies Are Evil: It's unclear if the Brigade are actual military soldiers or just a paramilitary group that styles themselves as soldiers, but they're organized as a military and are very much evil. Given that they have the equipment and manpower to fortify and hold large portions of D.C., including the Lincoln Memorial and Capitol Hill, it seems likely they're the real deal. Their ambient dialogue seems to suggest they're a core group of military fascists who have bolstered their ranks by recruiting able-bodied survivors who share their Social Darwinist philosophy and giving them military training and discipline. Bridger, who actually used to be in the military, expresses distain at the Brigade's military affectations, although that seems to be more about their wanton slaughter of prisoners and civilians rather than their effectiveness.
- Awesome, but Impractical: The opening CGI movie (which depicts the game's first post-tutorial mission) shows Grant shooting open a padlock to unleash a group of walkers into a Family camp as a distraction. You can do this in-game, but it's a horrible idea, as the noise the Family thugs make shooting the zombies will skyrocket the noise meter, spawning hordes throughout the level and making the game much harder for you.
- Big Good: Anderson, the leader of The Camp, is responsible for handing out missions and serving as your Mission Control, as well as being the narrator for the game's cutscenes, serving a similar role as Bain in Payday.
- Breakable Weapons: Weapons have a finite number of times you can bring them into a mission before they break. You can spend scrap to repair them, or acquire new ones. Weapons at 50% condition or lower are prone to jamming, which can get you killed in a pitched firefight.
- Close-Range Combatant: Aidan's specialization in shotguns, high health, and damage resistance perk all encourage a playstyle centered on rushing down human enemies and blasting them at point-blank range, relying on your damage resistance and health to let you tank their shots. Fortunately, shotguns can be silenced, and if you're quick enough this can actually be one of the "stealthiest" playstyles, but the increased enemy damage at higher difficulties makes it a lot less practical there.
- Early Game Hell/Earn Your Fun: This seems to be a core component of OVERKILL's game design philosophy. Even the early missions are extremely difficult for a level 1 player, especially a new player who has no idea what they're doing. Without more experienced players to boost you, beating the first real mission after the tutorial level is often a case of dying over and over again until the small amounts of XP you get from failing repeatedly eventually allow you to level up enough to beat it.
- Elite Mooks: Brigade soldiers are noticeably tougher than Family thugs, with better accuracy, more health, and military body armor. On the plus side, they also have better fire discipline than the Family, and are much less prone to skyrocketing the noise meter by firing wildly at nothing even if you're nowhere near them.
- Elite Zombie:
- Armored zombies (called Blockers) are zombified U.S. soldiers wearing full heavy body armor; you need to knock their helmets off before you can destroy their brains.
- Bloaters are a lot tougher than regular zombies (requiring multiple headshots to bring down) and explode when they get close or you manage to kill them.
- Escort Mission: You can randomly find NPC survivors in the levels; if you can lead them to the extraction area, you can have them join your community. Unfortunately, their A.I. is even dumber than the zombies, and they tend to either get stuck somewhere or run straight into a group of zombies and get eaten. Fortunately, survivors will randomly join your community through other means, so you're not reliant on finding them inside the levels. The end of the mission "Open Season" is very annoying because it forces you to do this with a plot-important NPC, who will often get your group killed by not following you properly and either getting stuck or eaten.
- Gameplay and Story Segregation: Family bandits will continue to raid your camp in random missions even after the Brigade wipes out the Family in "Open Season" and the Family's leader, Reina, joins your group. This is somewhat handwaved by ambient dialogue from Reina, who implies the Family is a loose-knit group of tough guys and thugs, so it'd make some sense for scattered remnants to continue to engage in raids outside her control.
- Heavily Armored Mook:
- Heavies/Brutes are equipped with riot shields, shotguns, and full heavy body armor; they can shrug off multiple headshots and can blow you away with a single close-range shotgun blast.
- Armored enemies are a lesser example; they wear body armor (sporting goods equipment for The Family, proper military body armor for The Brigade) that lets them soak more bullets than a normal Mook, and helmets that need to be shot off before you can headshot them.
- Incredibly Durable Enemies: The health of human enemies scales up drastically if you increase the difficulty; on hard difficulty (which the game forces you to play on about halfway through the Season 1 story missions) human enemies can shrug off multiple sniper rifle headshots before falling, until you manage to grind enough to obtain high-rarity firearms. Even on Normal difficulty, human enemies (even the Family thugs you fight early on) can survive a headshot from an assault rifle or pistol at anything other than absolute point blank range. If they're wearing a helmet or mask, they can survive even more headshots.
- Luck-Based Mission: Various progression objectives are random every time you play a mission. I.E. to open a gate sometimes you need to fix a forklift, sometimes you need to power a generator, and sometimes the forklift breaks down and you have to take a completely different path. Some of these paths are much easier than others. Notably, the mission "Doctor's Orders" is IMPOSSIBLE to complete playing solo if the exit to the mall is opened with a crank rather than a generator, as the zombies spawn right next to the crank and it is IMPOSSIBLE to crank the crank long enough to open the gate without being grabbed by endlessly respawning zombies.
- Mêlée à Trois: The game is based around three-way combat between your team, the zombies, and hostile human factions.
- Men Are the Expendable Gender: All of the human assholes you spend the game massacring are men. Though this sort of makes sense for the Brigade, which are based on the U.S. Military circa the early 00's (when the zombie outbreak started).
- More Criminals Than Targets: The number of footsoldiers The Family and later The Brigade have is rather mind-boggling considering how low the surviving human population is supposed to be. In a single mission you'll likely slaughter more assholes than The Governor had in his entire gang. Somewhat handwaved by the implication that the D.C. human survivor population is much larger than in rural Georgia where Sheriff Rick's odyssey takes place.
- Powerful Pick: One available melee weapon is the pickaxe, which Heather the Scout specializes in. It's actually one of the game's better weapons against zombies, killing them instantly with a single light attack to the headnote and having a quite fast attack rate and relatively low stamina cost. It's only real drawback is the lack of crowd control ability, since its heavy attack also is a single-target attack rather than a sweep like with many other melee weapons, and even then it's generally much more effective to eliminate several zombies with single quick light pickaxe strikes then try to sweep them all with a heavy attack from a staff or axe.
- Removing The Heador Destroying The Brain: Just like in the comics and TV show, there's basically no point in shooting a walker anywhere besides the head. Torso shots do essentially no damage to them and while you can cripple them with leg shots, they'll just keep crawling to attack you. This even applies to human enemies, due to your limited ammo and the fact they can often soak several torso shots before dropping.
- Respawning Enemies: Zombie hordes will show up out of nowhere to attack you periodically, based on how much noise you make firing unsilenced guns or triggering noise traps. At a full 3-star alert level, dozens of zombies will continuously spawn into the level to come after you.
- Resources Management Gameplay:
- You start each mission with minimum ammo, and every ammo pickup usually only gives you 1-3 bullets. Conserving ammo is a must. You also need to search the environment for the materials needed to craft charges for your special abilities, such as throwing molotov cocktails or dropping medic bags.
- You also need to balance your base resources as they get used up over time based on the number of NPC survivors you have back at home base.
- Revolvers Are Just Better: Zig-zagged. Revolvers deal more damage than semi-automatic pistols, but can't be silenced and generally hold less ammo and take longer to reload. The .44 magnum in particular deals more damage than most sniper rifles, and can one-shot headshot higher difficulty enemies that rifles require multiple headshots to kill. They can be good for camp defense missions, but their inability to be silenced generally makes them poor for exploration missions.
- Secret Character: Finding all the Bounty Hunter collectibles allows you to play as Bridger, an ex-military local community leader who appears briefly in one of the story missions. She specializes in assault rifles, revolvers, and axes, uses frag mines, and gains damage resistance after being injured (the damage reduction isn't as high as Aidan's similar skill, but Bridger gets a speed boost too).
- Shared Universe: With the comics. Overkill has flirted with the idea of characters from the comics, novels, Telltale games, and Road to Survival making appearances in the game. In fact, The Wanderer from the latter does in fact appear in-game.
- Solo Class:
- Grant the Tactician seems to be the preferred character for solo players; he's the Jack of All Stats, and his Marked For Death ability allows you to do bonus damage to enemies, which is most useful for allowing you to kill human enemies with a single silenced sniper rifle shot to the torso.
- Heather the Scout can be more difficult to play as, due to her low health and her crossbow needing to be reloaded after every shot, but with the right build she can be very powerful solo; her crossbow is silent and the bolts can be retrieved after being fired, and her pickaxe kills zombies with a single light attack to the head, has a decent swing speed, and uses relatively little stamina, letting her be very effective in melee especially if you upgrade your stamina and swing efficiency. If you know what you're doing you can mow through mobs of zombies and also silently clear out hostile survivor camps without causing enough noise to raise the horde alert level.
- Stealth-Based Game: The first real mission emphasizes the importance of stealth by dumping you in front of a horde of walkers that's way too big for you to fight your way through. You need to sneak through the neighboring apartments to get past them instead.
- Stone Wall: Aiden the Tank has the highest health in the game (5 health bars by default, compared to 4 for Grant and just 3 for Heather and Maya, plus he gains 5 extra health bars after upgrades rather than the usual 4), and his special ability gives him damage resistance for several seconds after he takes damage. However, his other stats (i.e. stamina) are lower to compensate.
- Support Party Member: Maya's perk increases her speed at reviving downed teammates and increases the health they regain from being revived. However, it has absolutely no effect if you're playing solo. Fortunately, her equipment (a med-bag with multiple uses) provides much better healing than standard bandages and gives her some ability to do solo runs.
- Unintentionally Unwinnable: After completing the mission "Home Sweet Home", your home base is destroyed and you need to finish the next mission, "Last Stop", in order to find a new home base. During this time, you cannot play other missions, level up any of your perks that require a base upgrade, or do any other activities. However, "Last Stop" is one of the most difficult and frustrating missions in the game, and if your character isn't strong enough to beat it you cannot go back and replay earlier missions to grind for experience or better weapons, essentially rendering the entire game into a permanently unwinnable state and making your copy of the game a worthless brick.