There seems to be a growing ambiguity about the “Immersive Sim”. It’s a term that gets thrown around a lot in discussions about games without a very clear notion of what it signifies, and it frequently causes confusion among the majority of participants who aren’t already versed in its jargon. The increased use of the term is matched by skepticism about its value, partly on the basis that the name itself is misleading, and partly on the basis that the classification it refers to is ultimately meaningless. As someone who spends altogether too much time thinking about “Immersive Sim” (or “ImSim”) games and their design, I thought it worthwhile to put forward my sense of the term and what it means in the hope of adding clarity to the discourse. Unfortunately, what follows is pedantic to a fault, and is unlikely to convince anyone on the other side of this debate. So at present, it will have to suffice as an articulation of my own ImSim cult ideology, which may at least provide a bit of perspective. So let’s get started.
Some history is warranted. “Immersive Sim” is a term that was originally coined by Doug Church [1] and popularized by Warren Spector [2] to refer to a canon of games by Looking Glass Studios and a few developers inspired by them in the 1990s and early 2000s. These comprise Ultima Underworld (1992) and its sequel (1993), System Shock (1994), and Thief: The Dark Project (1998) and its sequel (2000) by Looking Glass Studios, as well as System Shock 2 (1999) by Irrational Games in collaboration with LGS, Deus Ex (2000) by Ion Storm, and Arx Fatalis (2002) by Arkane Studios. This style of games more or less died out in the mid-2000s, with Deus Ex: Invisible War (2003) and Thief: Deadly Shadows (2004) from Ion Storm disappointing fans and failing to meet financial targets respectively. A slew of ImSim-adjacent titles like Vampire: The Masquerade — Bloodlines (2004), Pathologic (2005), Dark Messiah of Might and Magic (2006), and the S.T.A.L.K.E.R. series (2007-2009) borrowed some of the simulation elements of the prior titles, but with a lesser emphasis compared to other design priorities. Irrational Games’ spiritual follow-up to System Shock 2 in Bioshock (2007) was a resounding critical and commercial success, though it remains divisive among some diehard fans of early ImSims, many of whom reject its streamlined design (a category I would place myself under). Concurrently with the prior developments, Bethesda Softworks was inspired by Ultima Underworld to create their own real-time first-person RPG in The Elder Scrolls: Arena (1994), which featured similar design sensibilities but favored breadth over depth in terms of interactivity as well as the size and detail of game world, a trend which continued in TES: Daggerfall (1996), whose continent of Tamriel matched the size of Great Britain. This was reigned back in TES: Morrowind (2002), which features a hand-crafted world much smaller in scope, more comparable in scale to Bethesda’s subsequent TES: Oblivion (2006), Fallout 3 (2008), TES: Skyrim (2011), and Fallout 4 (2015) as well as Obsidian Entertainment’s Fallout: New Vegas (2010). While most agree Bethesda’s open world RPGs are not Immersive Sims, they nonetheless retain some Looking Glass design influences, and the company would help pave the way for the resurgence of the Immersive Sim in the following decade (notably, Bethesda lead designer Emil Pagliarulo is a Looking Glass alum who acted as a writer for Thief II).

After a relative absence from the industry outside of some titles that branched out into other areas, Immersive Sims re-entered public consciousness with Deus Ex: Human Revolution (2011) by a newly formed Eidos: Montreal and Dishonored (2012) by Arkane Studios, who had emerged from several canceled projects with a partnership with Bethesda Softworks. Both games were positively received and resurfaced interest in the Deus Ex and Thief games that inspired them. Follow-ups Deus Ex: Mankind Divided (2016) by Eidos: Montreal and Dishonored 2 (2016) and Prey (2017) by Arkane, the latter of which was a close spiritual successor to System Shock 2, were less financially successful than their predecessors, spawning concerns of a “second death of the Immersive Sim” [3][4]. At the same time, games like Metal Gear Solid V (2015), HITMAN (2016) and its sequel (2018), and Zelda: Breath of the Wild (2017) have incorporated elements of Immersive Sims into their designs beyond a superficial level, creating experiences that don’t really resemble Looking Glass games in terms of genre tropes and expectations, but do manage capture a similar spirit of open-ended problem solving with expressive toolsets and deep simulated interactivity (NOTE: I have not personally played the last four games, so take the preceding statement with a grain of salt). Additionally, there are a number of indie ImSim projects currently in development, seemingly on the coattails of the retro FPS revival occurring in the indie space, including the likes of Gloomwood by New Blood Interactive, Monomyth by Rat Tower, and Peripeteia by Ninth Exodus, which are similarly inspired by the pioneering titles in the ImSim design lineage.

As a result of the contrast between the Immersive Sim’s wide appreciation among fellow game developers despite niche appeal among players in the early days, as well as the influence it maintained both during its absence and its sudden explosion in popularity in the last decade, Immersive Sims are in the peculiar position of being simultaneously more popular and more poorly understood than ever. Much of this can perhaps be chalked up to the fact that the ImSim renaissance via the rebooted Deus Ex franchise and Arkane’s recent efforts has largely been concerned with remixing ideas from Looking Glass et al, staying largely within the confines of hybrid FPS/RPG genre trappings. The latter-day Deus Ex games, the Dishonored series, and Prey can all be located as direct or spiritual successors to classic ImSims, and all feature common tropes such as playstyle options for stealth and combat, character upgrade trees that unlock new abilities, level design featuring “locks” that can be opened by “keys” in the form of these chosen abilities, inventory and resource management, narrative choice and consequence, optional reading material for world-building, easter egg references like “0451”, and so on. These peripheral tropes have become synonymous with Immersive Sims in popular discourse to the point that classic ImSims that don’t possess them (e.g. System Shock, Thief) may be unrecognizable to players familiar only with modern titles. I will attempt to address this paradox by providing a coherent definition for the Immersive Sim that admits all the seminal titles, the modern entries that have followed directly in their footsteps, and even games which are not traditionally seen as Immersive Sims, but which nonetheless meet all of the same qualifications. In this framework, I’ll argue that the Immersive Sim is not actually a genre of games so much as it is a philosophy concerned with certain design principles. I said it was going to be pedantic, so let’s start with what a “game” is, and what a “game genre” ought to be.
In brief, I’d argue that a game consists of mechanics (actions the player can take), systems (rules governing interactions), and some form of challenge brought on by a goal. Typically, game genres are thus classified according to their mechanics, systems, and/or structure of challenges. First person shooters are defined by shooting mechanics; role-playing games by character development systems; roguelike/lite games by procedurally generated challenges with permadeath, etc. It is worth noting, then, that the canonical Immersive Sims share relatively few of these basic elements between them. Ultima Underworld (along with Arx Fatalis) is a dungeon crawler RPG set in a single interconnected game world. System Shock is a dungeon crawler FPS hybrid with the same world structure as Ultima Underworld but none of the NPC interaction and no RPG elements. Thief TDP and TMA are mission-based stealth action games with no RPG elements, minimal shooting, and linear progression of levels. System Shock 2 is an FPS/RPG similar to its predecessor but more focused on combat and character building than nonlinear exploration. Deus Ex is a stealth action/FPS/RPG where each mission can span multiple levels which cannot be returned to once the mission is complete. There are barely any shared genre trappings between every one of these games other than being real-time and playing from the first-person perspective – rather, they tend to hybridize elements from various game genres. However, most would agree that there is a design through line that intersects them all, owing to the collective sensibilities of their creators. Thus, the Immersive Sim describes a design philosophy rather than a genuine game genre in its own right. Given the small number of concrete commonalities between classic ImSims, any classification should ideally be constructed from the minimal set of characteristics shared between them all. The qualities that I believe characterize the Immersive Sim design philosophy are as follows:
- Real-time gameplay from the (usually first-person) perspective of a single player character
- Influence from role-playing games, particularly in promoting player agency
- Systems-driven gameplay with a focus on simulation
As I understand it, “Immersive” comes mostly from #1 since the player is directly behind the eyes of the player character in real time (this is debatable as immersion is a higher-order result of various factors which are highly subjective), and “Sim” mostly comes from #3, as the rules (systems) that define gameplay are largely derived from simulating interactions with the game world in a believable manner. The biggest thing that the name misses is #2, which is a subtler element to pin down since it’s both a comment of history (i.e. the ethos of Ultima Underworld was to make an immersive dungeon crawler RPG that replaced dicerolls with computer simulation wherever possible) and also of structure (the player should have open-ended goals that allow them to apply the various tools at their disposal in a logical manner). It’s #2 that seems to draw most players to ImSims as a sort of secret sauce that holds the experience together. Moreover, it’s more of a design goal than a descriptive quality, and thus has a subjective component that makes it rather difficult to concretely pin down. However, we can look for examples in classic ImSims.
While games like System Shock and Thief don’t contain any character development systems typical of role-playing games, they still offer meaningful agency in how the player tackles obstacles which resembles the improvisatory gameplay afforded by the open-ended rulesets of pen and paper RPGs. For example, in System Shock, the Beta quadrant of the Research level is bathed in total darkness, as the power has gone out to that sector. In many other games, the power breaker would have to be reset in another quadrant before the player can proceed in the area. This is an option in System Shock; however, light and dark are dynamically simulated and can also be affected by the player’s weapons. During my first playthrough, I decided to explore the Beta quadrant before I found the power breaker by lighting my way with my Sparq beam blaster, taking aim at the cyborg drones who ambushed me during the brief strobe of brightness following each shot. This is just one example of how ImSims can present problems using generic systems which afford emergent solutions, encouraging creative application of real-world logic to tangible problems. Similarly, in a Thief II mission like The Bank, the player will study the map and scout out the area to strategize how they’ll break in, planning the route to their objectives. As an alternative to the well-guarded main entrance, one player might first slip in through the basement window; another by climbing up to a second floor balcony; a third by a rooftop door to the meeting room rafters that can be rappelled down using rope arrows. Once inside, they’ll encounter various obstacles — human guards and patrolling robots together with noisy marble floors and brightly lit hallways which in turn can be circumvented by the player’s moss and water arrows, but since these are limited, they have to be used strategically. In my playthrough, I found that my most reliable option to reach the vault was to create chaos in the Guard Room from a dark perch and slip past in the confusion (I highly recommend The Playing Field’s breakdown and analysis of this level for more). Every player’s experience with the level will differ in major and minor ways, generating unique player stories in a vein similar to the collaborative storytelling of pen and paper RPGs.

Of course, RPG elements can be seen a natural fit for this type of experience, just as they are in pen and paper RPGs. There’s a split among ImSim enthusiasts who prefer the System Shock/Thief approach for its lack of any abstract character building systems vs. those who enjoy their inclusion which bears mention here, but as a person aligned slightly more with the latter I won’t dwell too much on the argument. With the player’s toolset limited by their character build choices, levels can be built with various opportunities such as as a locked door which must be picked open or a path blocked by a heavy object which must be lifted out of the way that is only available to a player with certain abilities unlocked, thus guaranteeing that players will have a unique experience based on their upgrade choices. In the case of Deus Ex, different routes will test multiple (player and character) skills, with branches and loops that afford a multitude of combinations in various character builds. Because character upgrades have a degree of granularity, this is also more nuanced than the binary ability gating seen in the modern Deus Ex games, as opening up paths will require different amounts of resources depending on character upgrades and equipment choices, adding a layer of long-term resource management to pathing decisions. Investing into technical skills doesn’t just open up options for tackling levels, but also can grant access to helpful items such as ammunition/grenades, lockpicks/multitools, medkits/biocells, or even weapon mods and augmentation upgrade canisters, which feeds back into stealth, combat, and exploration. Every player is expected to engage with these core tenets of gameplay, but they are given a large degree of agency in their approach. This is the mold in which post-2011 ImSims with RPG elements generally operate, though this is just one of many potential paradigms. Ultima Underworld, System Shock 2, and Arx Fatalis use their RPG elements to promote player agency via densely simulated object interaction moreso than lock-and-key level design — weapon degradation, light and physics manipulation with spells, damage type vulnerabilities, item crafting and alchemy, bartering systems, and control over AI states all interface with various character stats and skills to produce multiple methods of solving problems with benefits and drawbacks, while level obstacles are presented at chokepoints and force the player to use their tools to deal with them rather than finding an alternate way around as in Deus Ex or Thief.

Notably, other than playing from the third-person perspective, games like MGSV and Zelda: BotW seem to exhibit all 3 qualities shared by classic ImSims, even if they do not reproduce the genre tropes that have become typically associated with them. A design philosophy based around promoting player agency via real-time simulation is ultimately a rather broad thing, just as problems in the real world can be resolved by any number of possible approaches. However, this by no means makes the design philosophy all-encompassing — plenty of games are not primarily systems-driven (e.g. an action game like Devil May Cry is primarily mechanics-driven), and among those that are, many are built around abstract systems that require explicit tutorialization (e.g. Final Fantasy VII’s materia system is very deep and leads to a lot of agency in character building, but must be understood entirely in the context of its own abstract rules). The essential value of simulating phenomena familiar to the player is that systems can be implicitly communicated — the damage system in the first System Shock is highly complex, factoring in armor penetration, critical chance multipliers, and type vulnerabilities for both the source and target, but the effectiveness of ammo types is intuitively conveyed to the player via real-world expectations; hollow-point magnum rounds have low armor penetration but high chance to critically wound an organic mutant, while slug rounds have a better chance of piercing the thick metal plating of an armored cyborg. In this sense, Immersive Sim gameplay can be viewed as a sort of dialogue between player and game — the player asks “can I do this?”, and frequently the systems respond with “yes!”, encouraging targeted player experimentation in place of a one-way conduit of information from the game to player. This can certainly lead to emergent solutions to problems unforeseen by the designer, but the dirty secret of ImSim design is that much of the time, the designer explicitly planned for your novel approach. However, it’s precisely those moments in which generic systems interact with hand-placed designs in logical but unplanned ways that maintains the illusion of a simulation in which anything is possible. That sense of discovery clearly resonates with players on a primal level, and sets the Immersive Sim apart from other games after the RPG systems, hacking minigames, and conspicuously placed vents are stripped away.
The Immersive Sim is a design philosophy that’s inspired a lot of games across many genres, but for its own part seems increasingly pigeonholed by the genre conventions of the original games that pioneered it. Ultima Underworld, System Shock, Thief, and Deus Ex were wildly creative and notably distinct from each other in the kinds of worlds they simulated and the roles players were given to inhabit. While I’m happy to play new games that offer reverence to these classic games by incrementally refining and expanding on their ideas (there’s still plenty of room for creativity in that space), I’d also like to see some original takes on the Immersive Sim that offer wholly new experiences; player fantasies other than the hero Avatar, cyberpunk hacker, sneaky rogue, or secret agent; novel systems that simulate complex webs of interaction beyond security cameras linked to turrets and alarms. Thankfully, things need not end on such a wistful note. Tune in next time for a deep dive into an underappreciated Immersive Sim from 2019 that does all of these things and much more.
3 thoughts on ““Immersive Sim” is a Design Philosophy, not a Genre”