After a quick introduction into each game genre, I will make some general observations of how sound and music are traditionally used in these different flavours of games. Also, I will hint at some typical examples of PC games for each genre. However, not all games can always be clearly attributed to one or another of the categories mentioned below, which is why the following subdivision can only represent a broad generalization and is not intended to offer a comprehensive classification.

Games of this genre focus on quick reactions on the side of the players who have to find their way around a virtual world. Game objectives commonly include the completion of certain missions that often require the player to solve various puzzles or give demonstrations of skill in handling the player's avatar. Also, the player is often confronted with a number of enemies that have to be avoided or eliminated in order to successfully complete a stage – sometimes, the only goal of a game is to get from point A to B without running out of health or energy drained by enemy attackers.

In action games, the player usually experiences the virtual world from a first-person (i.e. natural) perspective or follows events through the view of a virtual camera positioned in some distance behind or above the player's character. Popular examples of the first case are QUAKE or HALF LIFE, whereas the latter variant is represented by games, such as TOMB RAIDER or SUPER MARIO 64.

		WOLFENSTEIN 3D Stereo sample from the 1992 game by id Software.    DUKE NUKEM 3D Sewer sounds from the 1995 game by 3D Realms.    QUAKE Typical scene from the 1996 game by id Software.    “Shields low!” Warning message from the 1998 game FORSAKEN by Acclaim.

The proper use of sound in action games can very much improve the player's perception of the virtual environment. In addition, sound can inform of status and provide vital clues to off-screen events, such as lurking enemies or pending danger from incoming vessels. With the advent of stereo soundcards, it became possible to even coarsely locate sources of sounds through the use of simple stereo panning (see sidebar examples). Some relatively early 3D action games, most notably DUKE NUKEM 3D by Apogee, already incorporated some degree of audio processing, such as simple reverb, filters or flanging effects to simulate certain environments, like sewer tunnels or large halls. Other games, such as DESCENT, included pre-processed sounds that offered a spatial impression.

Today, 3D graphics and audio are use more excessively in action games than in games of any other genre. By using 3D audio rendering and four-channel soundcards, sophisticated acoustic representations of virtual environments can be created that more and more closely resemble real-life situations. Also, compared to stereo panning, localization of sound sources can be vastly improved and expanded to a full circle encompassing the player – a much wider area than can be displayed on screen.

Musical soundtracks for action games can either be static or dynamic. In the first case, musical pieces are often composed and recorded in a studio to be included on CD-audio tracks that are played back during certain levels of the game. Other variants include the use of prefabricated MIDI and/or DIRECTMUSIC soundtracks. Since action games are often played for extended periods of time, the pieces of such a soundtrack tend to repeat more or less frequently, which can get quite annoying. Dynamic soundtracks, however, adapt to the player's action, certain events or environments. Creating such a musical accompaniment to the on-screen action represents one of the greatest challenges to game designers. See Part E of this work for a more detailed discussion of this.

Due to the nature of these games, graphic and acoustic depiction of violence is a commonplace phenomenon and has given rise to a heated discussion of this genre. Nonetheless, games of this category are enjoying an immense popularity and represent the driving force behind the development of increasingly powerful graphics and audio hardware to create more realistic and immersive 3D worlds.

Short history of important developments related sound and music in action games:

Year	Title	Company	Comments
1986	Wolfenstein 3D	id Software	First ever 3D-shooter, stereo-panning and distance-cueing allowed for crude localization of sound sources. Only one sound could be played at a time.
1993	DOOM	id Software	Realtime software mixing allowed for several simultaneous stereo voices. Use of ambient sounds.
1994	Duke Nukem 3D	3D Realms	One of the first games to offer real-time audio effects to simulate various environments.
1995	Descent	Interplay	Sound samples pre-processed using “Spatializer” software to offer a 3D effect.
1998	Half-Life	Sierra	The first game I was able to play in “real” 3D-audio, thanks to a 4-channel Creative SBLive! soundcard.

In general, games of this genre strive to faithfully re-create real-life situations, most commonly related to the execution of specific activities. The latter can be anything from driving a car to playing table-tennis. Games falling under this category include racing games (THE NEED FOR SPEED, RALLY CHAMPIONSHIP 2000), flight simulators (MICROSOFT FLIGHT SIMULATOR, FLIGHT UNLIMITED) and sports games ().

Besides realistic graphics, these games also have to produce convincing 3D sound to live up to their goal. In this respect, much is true of what has been said about action games before. But whereas it was possible or even desired to use unreal or larger-than-life effects with these, a simulation has to be much more accurate in terms of the chosen sounds. A very thorough observation of the simulation's real-world counterpart is necessary in order to obtain the required information for a successful reproduction. A car engine, for instance, will sound quite differently at a given RPM when under load compared to being in neutral gear. Furthermore, it is not customary to use sound to issue verbal warning messages, etc., except when also present in the simulated situation (e.g. the famous “Incoming” warning of a combat fighter computer).

Simulation games have not normally represented the cutting edge in audio on the PC to the same extent as action games. A notable exception to this was the 1997 military chopper simulation COMANCHE 3, which was the first game to support DOLBY SURROUND. However, in order to use this extra feature, the PC had to be connected to a DOLBY SURROUND amplifier driving five channels (left, right, center and two surround channels that were fed the same signal).

In this genre, music is often only used as background and can be readily replaced by any other piece that fits the players taste, or turned off completely, just like in normal life.

In games of this genre, the player usually assumes an abstract god-like position to control a simulated world seen from above. The objectives of such games can be manifold, but most commonly include successful expansion of territory, dominance over enemies or accumulation of a certain amount of a given item (credits, minerals, or even inhabitants). Depending on the nature of the game, special strategic, tactical, political, diplomatic or trading skills are required to varying extents. Popular titles of this game category are AGE OF EMPIRES, COMMAND AND CONQUER, THE SETTLERS or CIVILISATION.

Most often, only a two-dimensional or isometric projection of the game environment is given, sometimes with the ability to zoom in and out or to rotate the entire playfield. However, it is relatively uncommon for a player to assume a first-person perspective and become immersed into the virtual world of the game. A notable exception to this is the game DUNGEON KEEPER. Normally, these games exploit what I would like to call the “dollhouse”-factor (or “model railway” factor, for the boys) in human nature. It seems that the miniature representation of objects inside an artificial world exerts an attraction that only few can resist.

The way sound is used in strategy games is fundamentally different from action games. Since the world is seen from a top-down perspective, 3D sound spatialization is not normally applicable, though stereo-panning may be used to draw the player's attention to events taking place in an area left or right to the currently displayed window of the playfield. Accordingly, the main use of sound in games of this genre is to inform the player of certain situations or conditions as well as to furnish the simulated world with matching acoustic fragments of ongoing events and thereby making it more appealing to the player.

Music is used very much along the same lines as in action games. However, if a dynamic soundtrack is chosen, changes in pace are usually much less rapid and take place on a more gradual scale.

On the surface, some games of this type can look very much like action games, which is especially true for some fairly recent titles, like DEUS EX, that have a distinctly action-oriented character. Generally speaking, the essence of an adventure game is the plot – the story behind the course of events the player's character is faced with, which can consist of various layers and subplots. Aside from the interactive part of the game that involves exploring the world, using certain objects or interacting with other characters, non-interactive interludes are found in many adventure games. The latter are chiefly used to carry the story forward after a particular stage of the game has been completed or to familiarize the player with important events of a subplot. Also, the prevailing pace of an adventure game is normally much slower than that of a veritable action game, with ticking clocks or fading energy levels. However, the boundary between the two genres is rather soft: How much of a storyline is required for an action game to become an adventure? For instance, while I, for one, like to think of HALF LIFE as an action game, others might argue that is is an adventure game, considering the fact that it contains traces of a storyline. Popular (hopefully undisputed) examples of the adventure genre include BLADE RUNNER, the MONKEY ISLAND series, RIVEN and GRIM FANDANGO.

As far as sound is concerned, adventure games often incorporate large amounts of speech. Before the advent of the CD-ROM it was not possible to transport the required amount of data – rather, dialogue was represented as on-screen text, which went along with some degree of visual degradation. The first full-speech adventure game I remember was DAY OF THE TENTACLE by LucasArts – despite the fact that it did not offer improved graphics over previous LucasArts titles, the added speech clearly represented huge leap forward and made the game a lot of fun to play. A few phrases uttered by some of the characters still keep on ringing in my ears whenever I think of the game.

Ambient sounds used in an adventure game play an important role in transporting a credible impression of a certain location and add to the overall perception and feeling of a place. On the other hand, sounds can be used to provide important clues that may be beneficial for the player in order to complete his quest. In a few games, these acoustic hints are critical to a successful solution of certain puzzles – without them, the game cannot be completed. One such example is the game MYST, which uses acoustic codes in several places, instead of relying on visual ones.

Music plays a crucial role in most games of this genre. Since it can be used to carry moods, it represents an ideal tool to immerse the player into the story. Therefore, a great deal of attention is given to the soundtrack in most adventure games, which has resulted in some of the best music ever listened to on a computer. A few soundtracks, such as the FINAL FANTASY series or music from THE DIG, were even released on audio compact disc.

This category includes all other games that cannot be attributed to either one of the above genres, like various kinds of puzzles, card games, board games or brain teasers. Sound and music are hardly ever used in a very sophisticated way in these games, mainly to casually accompany the on-screen action.