"Stealth is the engine that makes this": Thick as Thieves is putting a multiplayer spin on everything we love about immersive sims

Fans of immersive sims like Thief or Deus Ex are used to being in positions where everything their character does has an impact, and seeing the effects of their many possible options rippling out into the game world. What they're perhaps not used to is another player swooping in and sending that world off on a whole new axis. Thick as Thieves aims to take immersive sims to the next level by making them multiplayer in a PvPvE "stealth action game" that pits rival thieves against one another in an alt-history cobblestone metropolis.

Thick as Thieves, from OtherSide Entertainment, revealed its first trailer during The Game Awards 2024 and is looking towards a PS5 2026 release date - though the launch date for PC and Xbox remains unconfirmed. OtherSide co-founder Warren Spector – himself a legend in the immersive sim genre thanks to his work on Deus Ex and ​​Ultima Underworld – told GamesRadar+ at a preview event ahead of TGAs, that the goal was to make "a stealth action game, with a capital S and a capital A."

"If you had all of the great stealth gameplay that makes classic immersive sims good, but your opponents weren't only A.I., or security, or traps, but they were other thieves who were just as clever as you were, that would be an incredible duel of wits," lead designer David McDonough explains.

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Slow and steady (sometimes) wins the race

"Wits" is a deliberate word choice, as there's no single correct way to pull off the perfect score. Each 20 to 30-minute session pits four players – each choosing a character with a signature skill that can be further customized with tools as the game progresses – against each other. All of them are trying to go after the main objective that their thieves guild wants them to swipe, but they also have individual, personal narrative quests (not to mention any other opportunistic looting they might get around to).

In edited footage from pre-alpha footage that the OtherSide team showed GamesRadar+, the player first takes to the streets. Thick as Thieves is set in a city that resembles Glasgow or Liverpool in the early 19th century, complete with streetcars, neon lights, and other hallmarks of the early electric age. Yes, there's also magic, but think less Wizarding World and more of a tool like any other, just with a high cost – McDonough notes that a player could use "a bound fairy in a jar" to steal a key," for instance. Spector describes the world as "a character" in the game, one that players would learn more about as they completed main missions in multiple sessions. That earned knowledge will in turn help thieves case the joint, so to speak, and the ongoing, live-support model OtherSide is pursuing suggests there will be plenty of ways to continue and expand on Thick as Thieves' story and gameplay with new content.

As we watch, the player thief attempts to get into a manor by using a seemingly magitek grappling hook to go to the roof. "We're really proud of our rooftops. They're an incredibly entertaining play space," chirps game director Greg LoPiccolo. Upon seeing a rival thief up there, the player instead heads for the sewers. He finds a clue, picks a lock, makes it up into the mansion, and sets a knockout gas trap behind him should any other thief try to gain access this way rather than one of the myriad of other possibilities.

"Everything you do ripples out into the possibility space of the game and comes back at you," McDonough explained. That goes for other players' actions, too. "You can come to a manor and find you have a hard time breaking in because another thief was there 10 minutes earlier."

We get to see that in reverse when our player knocks out another thief by ambushing them from behind. Direct combat like this is possible in Thick as Thieves, but it's difficult without the use of stealth and planning, and charging a computer-controlled guard head-on would likely be suicide. Eventually, the player was able to swipe the coveted object and run back to stash it – albeit with every other thief alerted that somebody had the MacGuffin.

This was how one playthrough went, but the next one would no doubt be quite different. There's a randomization element to each session, and a different approach might be required for a slightly tweaked mission. And then there are the other thieves who have their own changing strategies, too. One could kick in a door and blow past guards in a smash-and-grab attempt; another could be unseen in the rafters the entire time before swooping in to K.O. the first thief. These seemingly endless possibilities and viable playstyles make Thick as Thieves a more complex game than a shooter, where McDonough notes that factors like gear score, accuracy, and twitch skills tend to be-all and end-all factors that determine a winner.

"This game is much more of a mental game where a wide variety of success and failure is possible to a degree that is rare in all games — and especially in multiplayer games," he says. "Stealth is the engine that makes this."

Thick as Thieves is set to launch in 2026 on PC, PlayStation 5, and Xbox Series X. Until then, here are the best stealth games you should play to pass the time.