Emperor Frederick IV of House Corrino is desperate for the harvesting of the valuable drug melange (also known as "the spice"), found only on the planet Arrakis, to pay off all of his debt incurred on internecine wars with family members. To achieve this, he now offers the sole governorship of Arrakis to whichever of the three Houses (Atreides, Harkonnen, and Ordos) delivers the most spice for him. War begins as deputations from all three Houses arrive on Arrakis.
The player is a military commander from a House of their choice. In the first few missions the objectives are to establish successfully a base on an unoccupied territory of Arrakis, to harvest spice, and to defeat intruders. Later, when the three Houses divide Arrakis among them, the player has to assault and capture enemy territories. When the player dominates Arrakis on the world map, the two other enemy factions ally against their common enemy. The ultimate final showdown is the battle between the player's House against three enemy sides, among them Frederick's forces the Sardaukar (an unplayable elite force whose heavy infantry are particularly powerful). The introductory, mission briefing and endgame cutscenes are different for each House, in keeping with their very disparate world views. The weaponry and units also vary from house to house.
The player takes the role of the commander of one of the three interplanetary houses, the Atreides, the Harkonnen or the Ordos, with the objective of wresting control of Arrakis from the other two houses. House Ordos is not featured in the Dune novels and is mentioned only in the non-canon Dune Encyclopedia. The basic strategy in the game is to harvest spice from the treacherous sand dunes using a harvester vehicle, convert the spice into credits via a refinery and to build military units with these acquired credits in order to fend off and destroy the enemy.
The game map initially starts with a fog of war covering all area which is not covered by the player's units range of view. As the units explore the map, the darkness is removed. Unlike later games such as Warcraft II: Tides of Darkness, the fog of war is lifted forever with initial exploration, it does not become dark once more when units leave the area.
In addition to enemy incursions, there are other dangers; like the marauding gigantic sandworm, capable of swallowing vehicles and infantry whole but blocked by rocky terrain. The player can only build on rocky terrain, but must build concrete foundations before to avoid deterioration of the structures due to the harsh weather conditions although in general, structures will gradually decay over time regardless of the presence of those concrete slabs due to the aforementioned weather conditions, though the concrete saves repair costs in the long run. Spice fields are indicated by orange coloration on the sand, darker orange indicating high concentration. Some spice may be concealed as bumps on the terrain (a "spice bloom") that become spice fields when they are shot at, or when a unit runs over them (the unit is destroyed in the ensuing "spice blow").
The player is presented a map of the planet Arrakis before most missions, where they can choose the next territory to play in among two or three. This affects primarily the enemy house fought in the next mission, as all missions except the first two require the complete destruction of the enemy. Nine territories must be fought, irrespective of house, to reach the endgame.
Some key elements that first appeared in Dune II and later appear in many other RTS games include:A world map from which the next mission is chosen
Resource-gathering to fund unit construction
Simple base and unit construction
Building construction dependencies (technology tree)
Mobile units that can be deployed as buildings
Different sides/factions (the Houses), each with unique unit-types and super weapons
A context-sensitive mouse cursor to issue commands (introduced in the Mega Drive/Genesis version)
Completing higher missions gives authorization to use improved technology and higher-order weaponry unique to each House, ensuring varied game play. For example, House Harkonnen may be able to construct their Devastator tanks with heavy armor and ordnance but cannot build the similarly impressive Atreides Sonic Tank. The Ordos have access to the Deviator - a specialized tank firing a nerve gas that switches the allegiance of targeted units to Ordos for a limited period of time. The three Houses also are restricted in their production capabilities—House Ordos cannot build Atreides-style trikes, instead making the faster "Raider" trikes, while House Harkonnen constructs heavier but more expensive quad bikes.
A player can gain access to other Houses' special units by capturing an enemy Factory and manufacturing the desired units at the captured Factory (House Atreides' Heavy Vehicle Factory for Sonic Tank, House Ordos' Light Vehicle Factory for Raider trikes, House Ordos' Heavy Vehicle Factory for Deviator tanks, or House Harkonnen's Heavy Vehicle Factory for Devastator tanks). Note that a Deviator not owned by House Ordos still switches control of targeted units to House Ordos, and not to the side that owns the Deviator. Apparently Westwood was aware of this feature, since capturing a Sardaukar Heavy Vehicle Factory allows the player to build both the Sonic Tank and Devastator, but not the Ordos Deviator.
Buildings may only be built in rocky zones and connected to another existing building. To protect them from constant wear, the player must first place concrete slabs in the construction areas. Production buildings can be upgraded at a cost several times, allowing the production of more advanced units or buildings.
The final prize for the commander is the building of the House Palace from where superweapons may be unleashed on opponents in the final closing chapters of the game. The House Harkonnen superweapon is a long-range powerful but inaccurate finger of missiles called the Death Hand, whereas House Atreides may call upon the local Fremen infantry warriors, over which the player has no control, to engage enemy targets. House Ordos may unleash a fast-moving Saboteur whose main purpose is the destruction of buildings.
The AI of Dune II was one of the first used in RTS games, and while better than that of Herzog Zwei, it has various drawbacks. Examples include only attacking the side of the player's base facing its own, general inability to perform flanking maneuvers, and not rebuilding defenses. Recent research into the game's engine by fans revealed that the AI is in fact capable of more advanced strategy, but that a large part of these capabilities is unused due to consistently repeated errors in all of the game's mission scripts.
According to Virgin Interactive vice president Stephen Clarke-Willson in 1998, the development of Dune II began when Virgin Interactive planned to cancel the production of Cryo Interactive's adventure game Dune, after which he was given the task of figuring out what to do with the Dune license. After reading the original Dune novel, he decided that "from a gaming point-of-view the real stress was the battle to control the spice," so a resource-based strategy video game would be a good idea. It was around this time that employee Graeme Devine (who later founded Trilobyte) introduced to everyone at the Virgin office a real-time strategy game on the Sega Genesis / Mega Drive console called Herzog Zwei (1989). Clarke-Willson described it as a game where the player "kept clicking on stuff and then zooming off to another part of the screen. It was very hard to keep track of what was going on as an observer. Still, everyone liked it, it had fast action, and it was a strategy game." Virgin staff, including Clarke-Willson and Seth Mendelsohn (who later worked on the Ultima series), then went to Westwood Studios to talk about making a Dune game. According to Clarke-Willson, "Westwood agreed to make a resource strategy game based on Dune, and agreed to look at Herzog Zwei for design ideas." It later turned out that Cryo's game of the same name was not cancelled, and Westwood's real-time strategy game was called Dune II as a result.
Westwood Studios co-founder and Dune II producer Brett Sperry said in 2008 that conceptualization for the game began when Virgin president Martin Alper approached him with the offer of using their Dune license to produce a game, with the understanding that Cryo's Dune had been cancelled. In terms of video game design, Sperry stated, "The inspiration for Dune II was partly from Populous, partly from my work on Eye Of The Beholder and the final and perhaps most crucial part came from an argument I once had with Chuck Kroegel, then vice president of Strategic Simulations Inc ... The crux of my argument with Chuck was that wargames sucked because of a lack of innovation and poor design. Chuck felt the category was in a long, slow decline, because the players were moving to more exciting genres ... I felt that the genre had a lot of potential – the surface was barely scratched as far as I as [sic] concerned, especially from a design standpoint. So I took it as a personal challenge and figured how to harness realtime dynamics with great game controls into a fast-paced wargame." He also stated that, while "Herzog Zwei was a lot of fun," the "other inspiration for Dune II was the Mac software interface," referring to the "design/interface dynamics of mouse clicking and selecting desktop items" which got him thinking, "Why not allow the same inside the game environment? Why not a context-sensitive playfield? To hell with all these hot keys, to hell with keyboard as the primary means of manipulating the game!" During production, he found out that Cryo rushed to finish their game first, leading to Virgin publishing their game as Dune and Westwood's game as Dune II, despite Sperry protesting against this decision.
Other influences cited by Joseph Bostic (also known as Joe Bostic), the co-designer and lead programmer, and Mike Legg, one of the game's programmers, include the turn-based strategy games Military Madness (1989) and Civilization (1991), along with Herzog Zwei. According to Bostic, a "benefit over Herzog Zwei is that we had the advantage of a mouse and keyboard. This greatly facilitated precise player control, which enabled the player to give orders to individual units. The mouse, and the direct control it allowed, was critical in making the RTS genre possible.”
Originally released for DOS in 1992, Dune II was one of the first PC games to support the recently introduced General MIDI standard. The game audio was programmed with the middleware Miles audio library which handled the dynamic conversion of the game's MIDI musical score, originally composed on the Roland MT-32, to the selected soundcard. At initial release, the game's setup utility lacked the means to support separate output devices for the musical score and speech/sound-effects. This limitation was frustrating to owners of high-quality MIDI synthesisers (such as the Roland Sound Canvas), because users could not play the game with both digital sound effects (which MIDI synthesisers lacked) and high-quality MIDI score. Westwood later published a revised setup utility to enable users select a different soundcard for each type of game audio: digital speech, music, and sound effects.
In 1993, it was ported to Amiga and Mega Drive/Genesis. The Amiga floppy disk port is nearly identical in interface and game play to the PC version, albeit with less detailed graphics and frequent disk swapping (the game came on five disks). Save games are stored on a specially formatted disk and the game could also be installed to hard drive. In the Amiga version the player is limited to 32 units, but patches exist to allow the DOS version to have 255 units created and managed.
Two years later it was also brought to the Archimedes and Risc PC range of RISC OS computers.
The Mega Drive/Genesis port has fairly different building and unit graphics, a full-screen menu-less user interface suited for gamepad control, and no save game support, relying on access codes for accessing each level. Other additions include a music test option and a tutorial that replaces the mentat screen. Several ideas from this version, including the music track listing and the replacement of sidebar command buttons by a context-sensitive cursor, were used in Westwood's next strategy game, Command & Conquer.
The game was ported to Android in 2013. Also in 2013 a fan-made port for Pandora became available based on the reverse engineered game engine.
Computer Gaming World stated that the PC version of Dune II "easily outshines its predecessor in terms of game play ... a real gem", with "arguably the most outstanding sound and graphics ever to appear in a strategy game of its kind". Electronic Games gave the game a 92% score.
When the Amiga version of Dune II was released in 1993, it was met with positive reviews. CU Amiga magazine rated the game highly with 85%, praising the smooth gameplay and controls. Dune II received Amiga User International's Game of the Month award when it was reviewed in September 1993.
GamePro dubbed the Genesis version "one of the best war strategy carts for the Genesis", praising the controls, digitized speech, music, and fun gameplay. Electronic Gaming Monthly scored the Genesis version an 8 out of 10, commenting that the gameplay is not only addictive, but easy to learn, which they stated is highly unusual for a strategy game.
In 1993 Computer Gaming World named Dune II Strategy Game of the Year. The game was ranked the 11th best game of all time by Amiga Power in 1996. In 2004, this "legendary" game entered the GameSpy Hall of Fame. In Poland, it was included in the retrospective lists of the best Amiga games by Wirtualna Polska (ranked eight) and CHIP (ranked fourth). In 2012, Time named it one of the 100 greatest video games of all time.
Dune II was one of the most influential games in the real-time strategy genre, particularly in Westwood's own Command & Conquer series. Though not every feature was unique, its specific combination of a fog of war, mouse-based military micromanagement, and an economic model of resource-gathering and base-building became the hallmark of the RTS genre. It served as the template for subsequent real-time strategy games. Chris Taylor has stated that Dune II and Command & Conquer were great inspirations, driving him to leave Electronic Arts to create Total Annihilation.
Dune II also led to direct sequels: Westwood released a semi-remake for Windows in 1998 as Dune 2000, along with a PlayStation port in the same year. Westwood subsequently released Emperor: Battle for Dune in 2001.