The "immersive sim" is a video game genrenote that has existed in some form since The '90s, when it was codified by Looking Glass Studios and Ion Storm Austin, but has experienced a major comeback in The New '10s. Games in this genre aim to simulate a large believable lived-in 3D space wherein the players' avatar exists as an active physical entity, unlike in many other Simulation Game subgenres, — hence the "immersive" part. To this end, the developers combine clever game systems with advanced Video Game A.I. and afford the players maximum expression, while also refusing to hold their hand. Immersive sims commonly have following traits (although this list is neither normative, nor exhaustive):
- High levels of player intentionality and agency. Players are thrown into the virtual space and given goals to achieve and tools to use, but no predetermined paths to follow. Instead, they are expected to explore the environment, to assess their tools and resources, to make plans, and to adapt them on the fly in order to reach their objectives, relying on creativity and improvisation rather than on guessing the "correct" solution. To avoid overwhelming new players, the designers may offer some entry points and starting suggestions, but these are never rigid paths to be followed for the rest of the game/level.
- High systemicity. The game is governed by global rules, properties, and mechanics (such as the Physics Engine and NPC Scheduling) that work consistently throughout, with minimal use of systemic exceptions like Scripted Events, one-off animations, and cutscene setpieces. Immersive sims also tend to recycle previously introduced elements and obstacles in new and different contexts.
- Emergence. Interactions between various game subsystems facilitate emergent combinations thereof that the developers did not explicitly code into the game. Combined with high player agency, this also enables the Unexpectedly Realistic Gameplay characteristic of the genre.
- Consistency. As noted above, special cases and one-offs are generally few and far-between: e.g. there are no Invisible Walls and no Story-Driven Invulnerability — but even if an important NPC bites the dust, there is no Game Over, either, and the simulation just carries on. In fact, player character's death is often the only explicit failure state.
- High reactivity. The game world reacts to the player's actions and observably evolves over time. Story Branching often occurs not via explicit (dialogue) choices, but through gameplay actions, including ones that may appear like Script Breaking at first. To enhance reactivity, developers of immersive sims also tend to prioritize sophisticated AI (or at least, AI that appears sophisticated enough to be credible at its role).
- High physicality. The player character's body is a tangible object that exists in the game's universe, and is governed by said universe's laws. Magic, if it exists, will have a "tactile" feelnote . Critical Existence Failure is often averted, and the game may even account for how an injury was sustained and to what body part. The game may feature inventory management, and the player may be vulnerable to attack while accessing the inventory. More modern immersive sims are all but guaranteed to have a physics engine, which may be integrated into gameplay. Presentation-wise, this means that First-Person Ghost is often averted and a Diegetic Interface may be used.
- Non-linearity. Both in terms of Story Branching and level design. An immersive sim needn't be open world—most aren't—nor need it allow players to freely revisit old levels, but each level will feature many sidepaths, loads of alternate routes, secret areas (often with hidden Story Breadcrumbs), and small touches that create the impression of a real, lived-in place that does not exist solely for the player. To this end, immersive sims very often break The Law of Conservation of Detail.
Because the genre had historically evolved under the expectation that Virtual Reality technology was just around the corner, games in it often feature Unbroken First-Person Perspective and Diegetic Interfaces to improve their Player and Protagonist Integration, although this is not a requirement. Exposition and World Building tend to be handled through environmental storytelling, with Story Breadcrumbs scattered throughout the game world to encourage exploration thereof, and Back Tracking is a common activity — in this, the genre is similar to Environmental Narrative Gamesnote . Many games in it also contain nods to the number 0451note , in reference both to the original System Shocknote and to Fahrenheit 451.
The term "immersive simulation" was coined in 2000 by Warren Spector, the grandfather of the genre who had worked at both Looking Glass and Ion Storm. Spector, however, instead attributes it to Doug Church, also of Looking Glass Studios. Church and the Looking Glass co-founder Paul Neurath are usually named as the genre's "fathers", as it was them who laid its basic design foundations.
Because the term was obscure for many yearsnote , most games in this genre have traditionally been classified as first-person shooters on the higher end of the Fackler Scale of FPS Realism, stealth games, Survival Horror, or Western RPGs instead. That said, many games in the Wide Open Sandbox and stealth genres tend to incorporate elements of the immersive sim genre without going all the way into the Emergent Gameplay territory. Examples of these include Bethesda's Radiant AI-based RPGs (The Elder Scrolls from Oblivion onward, Fallout 3 et seq.) and the latest Hitman reboot. The Survival Sandbox shares the immersive sim's focus on emergent gameplay, but tend to be less focused on telling a coherent story.
The universally-acknowledged "Immersive Sim Canon" consists of:
- Arx Fatalis (2002, Arkane), intended as a Spiritual Successor to Ultima Underworld, is likewise set in a giant underground cavern populated by a simulated Fantasy Kitchen Sink of various creatures. The player character's task is to find a way to prevent the arrival of a God of Evil by manipulating the game systems to obtain a weapon strong enough to banish him. Notably, there is no dialogue system, and the player instead makes Story Branching choices, including different quest resolutions, exclusively through in-game actions.
- BioShock (2007, Irrational) sees the player trapped in an Underwater City of Rapture, once utopian, but now fallen to anarchy and civil war. It features the iconic splicers, Big Daddies. and Little Sisters. However, unlike earlier immersive sims, its exploreable areas are highly linear, there are less ways to interact with the world, and the game is heavily scripted, sparking some debate over whether or not it should be classified as a first-person shooter instead. Furthermore, the game's big twist can be seen as a deconstruction of the genre, explicitly denying players any form of agency on what is arguably the most important decision in the game, and revealing that they only had as much as the Big Bad — and, by extension, the developers — allowed them.
- BioShock 2 (2010, 2K Marin) returns to Rapture, although a decade into the future and even more decrepit. Much like its predecessor, its status as an immersive sim is somewhat questionable.
- BioShock Infinite, on the other hand, is usually not considered part of the genre, due to its levels being even more linear and an even heavier emphasis on First-Person Shooter combat mechanics than the previous games. Its two-part DLC Burial at Sea, however, was a deliberate return both to Rapture and to the immersive sim mechanics of the previous two games (part two even includes a challenge "1998 Mode" as a throwback to the original Thief).
- Consortium (2014, Interdimensional Games) was made as a Spiritual Successor to old-school immersive sims, especially to Deus Ex. It emphasizes player choice immensely, in terms of both gameplay and story-branching. Indeed, one possible ending is for the player to complete the game without having solved the central mystery. Is setting — the Cool Plane that serves as the mobile HQ for the intelligence agency the player character serves — also evokes the closed-off space station of System Shock (sans the Survival Horror elements). This setting inevitably means that Consortium has probably the narrowest scope of any of the "canonical" immersive simsnote , but the game's nonlinearity and narrative openness goes some way to counterbalancing this.
- As of 2020, a Sequel titled Consortium: The Tower is in the alpha stages of early access on Steam. It promises to keep its predecessor's narrative openness, while offering a larger setting and even more freedom.
- Deus Ex (2000, Ion Storm Austin) is considered one of the two great Trope Codifiers of the genre (alongside System Shock), and the game Warren Spector is most proud of. Set in a Cyberpunk, Conspiracy Kitchen Sink future, the game follows the Thief model of distinct missions and simulated level hubs, but allows the player character JC Denton to navigate them in any way and sequence imaginable. It was also one of the earliest games to make action-based and stealth-based walkthroughs equally viable, gameplay-wise.
- Deus Ex: Invisible War (2003, Ion Storm Austin) improved upon the reactivity of the story and game world, but its levels were much smaller and simpler than those of its predecessor, as a result of designing the game around the technical limitations of consoles. Another point of contention was the streamlining and simplification of many of the RPG elements of the previous game. Both contributed to the game's poor reception.
- Deus Ex: Human Revolution (2011, Eidos Montreal) had streamlined the first game's formula, albeit still allowing for emergent gameplay (such as hacking an automatic turret and hauling it to the next boss arena). It also features several Deadly Shadows-like hub levels from which the main story missions can be accessed.
- Deus Ex: Mankind Divided (2016, Eidos Montreal) improved upon the Human Revolution's immersive mechanics, particularly in its central hub level of the futuristic Prague, as well as added more options to tackle in-game challenges and affect different outcomes.
- The Dishonored series by Arkane Studios was one of the games that revived this genre for The New '10s, becoming a Gateway Series for players unfamiliar with it, as well as updating it to accommodate faster-paced playstyles. Unlike Thief, the Player Character may use both stealth, and open violence, or any combination thereof to assassinate (or to otherwise put out of commission) his marks, he can also use magical and technological tools to achieve his goals.
- Dishonored (2012, Arkane) is set in the plague-stricken city of Dunwall and with each level simulating the behavior of city guards, civilians, zombie-like weepers, and wildlife (e.g. rats). The Knife of Dunwall and Brigmore Witches DLC duology starring the assassin Daud follows the same model, at one point even simulating an all-out Mob War between two Dunwall gangs.
- Dishonored 2 (2016, Arkane) follows in the previous game's footsteps, albeit moving the bulk of the action to a different city, Karnaca.
- Dishonored: Death of the Outsider (2017, Arkane) is still set in Karnaca, but lets you play as Daud's apprentice Billie Lurk instead.
- Prey (2017, Arkane) strongly resembles System Shock in that it is set on an abandoned Talos I space station overrun by the alien Typhon. The station is one continuous interconnected zone, inhabited by a variety of Typhon creatures and a handful of human survivors, including the player character Morgan Yu. Like Arx Fatalis before it, the player's in-game actions are entirely what determines the plot's branch-points. The Mooncrash DLC further experiments with the boundaries of the immersive sim genre by adding elements of Roguelike into the mix, like randomly generated settings, enemy placement, and objectives.
- System Shock (1994, Looking Glass) is often listed as one of the two great Trope Codifiers of the genre (alongside Deus Ex), being Looking Glass' first original project. Its setting, the Citadel space station, is a single multi-layer zone controlled by the malevolent AI with a god complex and populated by robots, cyborgs, and mutants it controls. Among other things, System Shock introduced to the genre and popularized the After the End settings (often involving epidemics and/or societal collapse, thus justifying even the most extreme styles of play) with few speaking NPCs, and Apocalyptic Logs as the main storytelling medium.
- System Shock 2 (1999, Irrational) is set some time after the first game on two docked spaceships, the Von Braun and the Rickenbacker, after both have been overrun by a mutagenic alien hive mind known as "the Many".
- System Shock 3 (TBA, OtherSide) is currently in development, with Warren Spector and Doug Church back at the helm, and promises to be true to its predecessors' principles.
- The Thief series (1998-present) is universally considered one of the genre-codifying titlesnote . This is due to its highly systems-based stealth gameplay, its organic problem-solving elements, and its sprawling, open-ended levels that can be navigated in many ways. However, all four titles in the series deviate from traditional immersive sim conventions, at least on their higher difficulty levels, by restricting the player's ability to use violencenote , and giving players who broke these rules an automatic Game Over. In traditional immersive sim design, a game should end with the player character's death, or with a Non-Standard Game Over that is very tightly woven into the narrative. While an immersive sim certainly could force nonviolent play, this would traditionally be done by just not giving the player any weapons (or by making combat prohibitively difficult), whereas Garrett always carries a sword, a dagger, and/or arrows whose usage the rules inorganically restrict.note
- Thief: The Dark Project (1998, Looking Glass) is remembered primarily as one of the early success stories of the Stealth-Based Game, because of its heavy emphasis on avoiding detection,note but the sneaking itself was very much based in emergent problem-solving within a largely-unscripted game world (one particular innovation was the intricate simulation of light, shadows, and noise). It was also the first entry in the genre to ditch the "single interconnected world" model in favor of smaller sequential levels, each representing a location within a much larger (nameless) City.
- Thief II: The Metal Age (2000, Looking Glass) scaled down the fantasy elements of the first game, such as non-human monsters and maze-like dungeons, in favor of making the City appear and behave more like a realistic urban environment. It also expanded the protagonist Garret's toolset with new technological tools.
- Thief: Deadly Shadows (2004, Ion Storm Austin) introduced to the series a central hub level, consisting of several districts of the City, from which the plot mission locations are accessed and which are unlocked for exploration gradually as the story progresses. The AI was also dramatically improved compared to the first two games, with alerted guards becoming downright relentless in their searching on the higher difficulty levels. This game also closed the last immersion-breaking gap of the previous games, transforming their shopping screens between missions into an in-universe interaction. Paradoxically, the hub-based world design was seen in some respects as a step away from immersion: the hardware limitations of the time, combined with the game's cross-development for PC and consoles, forced the developers to break the (theoretically interconnected) hub world and all levels into loading zones.note
- The 2014 reboot by Eidos Montreal, however, is generally not considered part of the genre anymore, for much the same reasons as BioShock Infinite: more linear level traversal with fewer opportunities for exploration; reliance on scripted events; reactive, rather than proactive AI; and a smaller, yet more specialized toolset for overcoming challenges. One change that is often cited to illustrate the difference between simulated and scripted worlds is that the rope arrows in the new Thief can only be attached to specific hotspots placed by the level designers, rather than to any wooden surface (including freely moveable wooden crates), like in the older games.
- Ultima Underworld: The Stygian Abyss (1992, Looking Glass) is usually named as the Trope Maker of the genre. A Spin-Off of the Ultima series, it put the recurring dungeon of the Stygian Abyss into the focus, simulating its massive and complex multi-level ecosystem in real time. The Avatar found himself thrown into the Abyss with an overarching task to free a kidnapped damsel from a powerful demon, but no obvious path towards it, requiring the players to try out different strategies and to improvise. Warren Spector's inspiration for this emergent approach to in-game problem solving came both from Dungeons & Dragons and from watching a playtester solve an Unwinnable by Mistake puzzle in Ultima VI by exploiting the fact that his animal companion Sherry the Mouse could squeeze under a locked door and open it from the other side. Lessons learned from UU influenced both Ultima Underworld II: Labyrinth of Worlds (1993, Looking Glass) and the now-legendary Ultima VII to a considerable degree.
- Underworld Ascendant (2018, OtherSide) is a Kickstarted Spiritual Successor to Ultima Underworld (would be a sequel if not for trademark issues) developed by many of the same people, led by Paul Neurath himself. It simulates the Stygian Abyss as a massive underground ecosystem and society, and the developers have created what they call the "Improvisation Engine" to make sure players always have several ways to reach their goals.
Other games featured on some Immersive Sim lists but not on others:
- Alien: Isolation (2014, Creative Assembly), while lower in player agency than most immersive simsnote , is often listed as one, mostly owing to its extremely sophisticated and systemic AI.
- Crysis (2007, Crytek) and its 2009 stand-alone expansion Crysis: Warhead are not traditional immersive sims, having more in common with the First-Person Shooternote . However, the sprawling levels of Crysis's first half and almost all of Warhead, the many tools and powers players can use, the absence of artificial failstates (besides a late-game Escort Mission), and the first game's Unbroken First-Person Perspectivenote reflect the immersive sim ethos. Incidentally, the Nanosuit gives its wearer powers reminiscent of JC Denton's augmentations.
- Dark Messiah (2006, Arkane Studios) was designed as a spiritual successor to Arx Fatalis and has many of Arkane's signature touches: highly-reactive environments which encourage the player to be a Combat Pragmatist, branching skill trees, and gleeful use of the Source physics engine. It was by far Arkane's most purely action-focused game until 2019's Wolfenstein: Youngblood, which puts it in a BioShock-esque limbo of being either a very reactive action game with RPG elements, or a mechanically minimalist immersive sim.
- Dead Space (2008, EA) is sometimes included on lists of immersive sims for its atmospherics, its level design, its memorably involved combat mechanics, and its unusual synthesis of a Diegetic Interface with a third-person perspective. This classification is controversial, however — probably the most controversial entry on this list — and none of its sequels are labeled as immersive sims by anyone.
- Far Cry 2 (2007, Ubisoft) is an open-world First-Person Shooter that has, as of 2020, earned the "Immersive Sim" tag on the Steam Store. It embraces immersive sim conventions like Unbroken First-Person Perspective, a Diegetic Interface-style world map, and an atmospheric, highly reactive environmentnote . Even its polarizing experimental mechanics, like its malaria system, its total lack of a targeting reticle, and weapon degradation, evoke the immersive sim philosophy. Unfortunately, while its world is reactive, it lacks persistencynote , and it loses more points for the unscaleable rock formations cluttering its map, that can make the sandbox feel paradoxically linear.
- Firewatch (2016, Campo Santo) is an Adventure Game that borrows a lot of elements of the genre to immerse the player in its world, from an Unbroken First-Person Perspective and Diegetic Interface elements like the map and the compass, to real-time conversations and Story Breadcrumbs scattered all over the place and not walled-off by any artificial (non-diegetic) barriers.
- Hitman (2016, IO Interactive) transplants the series' core stealth assassination gameplay into a highly systemic setting, governed by global rules and combinable mechanics set in vast, nonlinear maps, very much like in many of the best immersive sims. It breaks from genre conventions by being entirely third-person, however, and relies on scriptingnote to maintain the series's tradition of "signature" kills.
- 2006's Hitman: Blood Money foreshadowed the 2016 reboot's immersive sim-wards turn, with levels being significantly more open than those of the first three games, Agent 47 being able to move through the environment more freely, multiple ways to complete objectives, and even tried to create a cause-and-effect relationship between levels with its "Infamy" systemnote .
- The Legend of Zelda: Breath of the Wild (2017, Nintendo) expands the traditional Zelda exploration with strongly systemic gameplay that facilitates extensive player agency and emergence. However, while taking obvious cues from immersive sims (like a post-disaster setting), BotW still maintains numerous gameful elements that preclude full immersion.
- Neon Struct: Die Augen der Welt (2015, Minor Key Games) can be described as a minimalist, miniature, synthwave-styled tribute to Deus Ex with a greatly increased emphasis on stealth, and a shadow-based system reminiscent of Thief'snote .
- The Occupation (2019, White Paper Games) brings the immersive sim to a more down-to-earth setting, putting you in the shoes of an investigative journalist/whistleblower nosing around a government office building in a slightly dystopian 1980s London. Besides boasting immersive sim's usual dynamic AI, heavy exploration, and organic approaches to obstacles, The Occupation adds the unusual step of applying a hard, real-world four-hour time limit: If you start a game, get distracted, and forget to pause it, then the game's story can end with your character having dawdled and smoked cigarettes on an office balcony.
- Pathologic (2005, Ice-Pick Lodge) is set in an unnamed steppe town ravaged by a mysterious epidemic, and the player steers one of three variously eccentric characters in an attempt to find a cure. Notably, the game runs in actual Real Time and always ends after 12 in-universe days, and it is entirely possible to miss the vast majority of the story events unless you know exactly when and where the next one will occur.
- The Portopia Serial Murder Case (1983, Chunsoft) was the first game to have most of the key immersive sim elements seven years before the founding of Looking Glass, making it arguably an Ur-Example. It was a first-person adventure game with an open world, character AI, choices and consequences, non-linear game design, open-ended narrative told through notes and diaries, interactive environments, emergent gameplay, allowed multiple ways to achieve objectives, and lacked failstates.
- While the Splinter Cell series (2002-ongoing, Ubisoft) as a whole does not belong to the immersive sim family, its third installment, Chaos Theory (2005), comes very close for a third-person game. It kept the first two games' uncompromising demands that the player use stealth, but gave Sam Fisher a much more varied arsenal of tools and weaponsnote , and had a fairly nonlinear level designnote , with players routinely having multiple ways to complete objectives, in multiple ordersnote . This was a dramatic change from the first two games, which were not just linear but often had only one "correct" way to proceed, making them akin to puzzle games. It also offered systemicity beyond any of the prior or subsequent titlesnote . It also allowed the player to screw up but still finish the levelnote : while Sam's superiors berate him if he gets needlessly violent, there are only a few levels where the game, with plot-relevant justifications, fails you should you kill someone.
- S.T.A.L.K.E.R. series (2007-2009, GSC Game World) is set in the vast Zone of Exclusion surrounding the Chernobyl nuclear power plant, which, in this timeline, had spawned a large number of bizarre anomalies and mutants. The player character is a "stalker" (a professional Zone trespasser) and must navigate the simulated environment and ecosystem of the Zone to survive.
- Subnautica (2018, Unknown Worlds Entertainment) is a rare Survival Sandbox game to not be procedurally generated, but rather to offer vast, intricately-designed sandbox, with elements reminiscent of Metroid Vania. Setpieces are few and far between, the developers went to great lengths to create multiple consistent underwater biomes, object permanence is a core gameplay mechanic, and while the diving system is jam-packed with Acceptable Breaks from Realitynote but these decisions ultimately contribute to a uniquely immersive gameworld.
- Vampire: The Masquerade Bloodlines (2004, Troika Games) is a Western RPG that, despite its numerous explicit ludic abstractions (it was based on a Tabletop RPG system, after all), manages to create a powerful sense of real space with its Gothic, vampire-run Los Angeles, with huge levels and far-reaching choices. One level in particular, the Ocean House, is often cited as a hallmark of immersive space design. It is not universally accepted as a true immersive sim, though, because of the player character's relatively limited ability to interact with the world's physical elements despite having the famous Source Engine at its disposal and its often-clunky handling which can make the gameplay feel like it's governed more by dicerolls than by the player's input.
- It's generally agreed that We Happy Few (2018, Compulsion Games) set out to be an immersive sim in the vein of BioShock, albeit with a greater focus on survival and procedurally-generated elements. There's less consensus on how well it achieved those goals, but...