2.5D in the context of "Dungeon Master (video game)"

Doom is a 1993 first-person shooter game developed and published by id Software for MS-DOS. It is the first installment in the Doom franchise. The player assumes the role of a space marine, later unofficially referred to as Doomguy, fighting through hordes of undead humans and invading demons. The game begins on the moons of Mars and finishes in hell, with the player traversing each level to find its exit or defeat its final boss. It is an early example of 3D graphics in video games, and has enemies and objects as 2D images, a technique sometimes referred to as 2.5D graphics.

Doom was the third major independent release by id Software, after Commander Keen (1990–1991) and Wolfenstein 3D (1992). In May 1992, id started developing a darker game focused on fighting demons with technology, using a new 3D game engine from the lead programmer, John Carmack. The designer Tom Hall initially wrote a science fiction plot, but he and most of the story were removed from the project, with the final game featuring an action-heavy design by John Romero and Sandy Petersen. Id published Doom as a set of three episodes under the shareware model, marketing the full game by releasing the first episode free. A retail version with an additional episode was published in 1995 by GT Interactive as The Ultimate Doom.

A first-person shooter (FPS) is a video game centered on gun fighting and other weapon-based combat seen from a first-person perspective, with the player experiencing the action directly through the eyes of the main character. This genre shares multiple common traits with other shooter games, and in turn falls under the action games category. Since the genre's inception, advanced 3D and pseudo-3D graphics have proven fundamental to allow a reasonable level of immersion in the game world, and this type of game helped pushing technology progressively further, challenging hardware developers worldwide to introduce numerous innovations in the field of graphics processing units. Multiplayer gaming has been an integral part of the experience and became even more prominent with the diffusion of internet connectivity in recent years.

Although earlier games predate it by 20 years, Wolfenstein 3D (1992) was the highest-profile archetype upon which most subsequent first-person shooters were based. One such game, considered the progenitor of the genre's mainstream acceptance and popularity, was Doom (1993), often cited as the most influential game in this category; for years, the term "Doom clone" was used to designate this type of game, due to Doom's enormous success. Another common name for the genre in its early days was "corridor shooter", since processing limitations of that era's computer hardware meant that most of the action had to take place in enclosed areas, such as corridors and small rooms.

Turbo (Japanese: ターボ, Hepburn: Tābo) is a 1981 racing video game developed and published by Sega for arcades; in North America, it was distributed by Sega/Gremlin. Designed and coded by Steve Hanawa, the game received positive reviews upon release, with praise for its challenging and realistic gameplay, 2.5D color graphics with changing scenery, and cockpit sit-down arcade cabinet. It topped the monthly Play Meter arcade charts in North America and ranking highly on the Game Machine arcade charts in Japan.

The game was manufactured in three formats: standard upright, cabaret/mini, and a seated environmental/cockpit. All three versions have a steering wheel, a gearshift for low and high gears, and an accelerator pedal. The screen is a vertically oriented 20-inch raster display. In addition to the on-screen display, there is an LED panel to the left of the screen that displays the current player's score and the high score table. There are also lighted oil and temperature gauges on either side of the steering wheel. Turbo was ported to the Colecovision and Intellivision consoles.

Q*bert (/ˈkjuːbərt/ ) is a 1982 action video game developed and published by Gottlieb for arcades. It is a 2D action game with puzzle elements that uses isometric graphics to create a pseudo-3D effect. The objective of each level in the game is to change every cube in a pyramid to a target color by letting Q*bert, the on-screen character, hop on top of the cube while avoiding obstacles and enemies. Players also use a joystick to control the character.

The game was conceived by Warren Davis and Jeff Lee, the latter of whom designed the titular protagonist and original concept, which was further developed and implemented by Davis. Q*bert was developed under the project name Cubes.

A tile-based video game, or grid-based video game, is a type of video game where the playing area consists of small square (or, much less often, rectangular, parallelogram, or hexagonal) graphic images referred to as tiles laid out in a grid. That the screen is made of such tiles is a technical distinction, and may not be obvious to people playing the game. The complete set of tiles available for use in a playing area is called a tileset. Tile-based games usually simulate a top-down, side view, or 2.5D view of the playing area, and are almost always two-dimensional.

Much video game hardware from the late 1970s through the mid-1990s has native support for displaying tiled screens with little interaction from the CPU.

Isometric video game graphics are graphics employed in video games and pixel art that use a parallel projection, but which angle the viewpoint to reveal facets of the environment that would otherwise not be visible from a top-down perspective or side view, thereby producing a three-dimensional (3D) effect. Despite the name, isometric computer graphics are not necessarily truly isometric—i.e., the x, y, and z axes are not necessarily oriented 120° to each other. Instead, a variety of angles are used, with dimetric projection and a 2:1 pixel ratio being the most common. The terms "3/4 perspective", "3/4 view", "2.5D", and "pseudo 3D" are also sometimes used, although these terms can bear slightly different meanings in other contexts.

Once common, isometric projection became less so with the advent of more powerful 3D graphics systems, and as video games began to focus more on action and individual characters. However, video games using isometric projection—especially computer role-playing games—have seen a resurgence in recent years within the indie gaming scene.