Dune II: The Building of a Dynasty/Glitches

While there were no "built in" cheat codes for the computer versions of Dune II, game settings could easily be manipulated by editing the "scenario.pak" file using a text editor. These settings include:
 * Amount of starting credits
 * Maximum number of units allowed
 * Units and buildings the player has at the beginning of each scenario
 * Enemy units and buildings at start of each scenario
 * And even allowing the player to partially control Sandworms (they do not take orders too well and will still consume the players units if the chance arises).

Changes could also be made to allow the purchase of specialized units from the Starport. Sonic Tanks, Devastators, Deviators, and Saboteurs could be purchased by the player regardless of what House was chosen. Unfortunately, Deviators will always change the loyalty of targeted units to Ordos, even if the Deviator belongs to Atreides or Harkonnen.

Money for nothing
You will need at least two harvesters, or one harvester and the ability/funds to build another one.

If you are a little short of spice around your base or if most of it is near the enemy base and you don’t feel like risking your harvester each time its harvest time, once your harvester is 99% move him to an area close to your base (away from where the enemy is attacking you so that the sand isn’t filled with holes) and kill/destroy your harvester with your tanks (or whatever is available to you). The amount of spice that will disperse over the sand in the explosion is at least 3 times greater than what the harvester contained. You can repeat this as many times as needed, and you can even re-spice whole maps if desired.

Miscellaneous
In the original (DOS) version:
 * There is a global limit on structures and units which curiously encompasses both the human player's and those of the CPU (the computer-controlled opponents). This severely limits the size of the human player's army when the CPU's army starts big on the later missions. To work around this the player has first to take "small bites" out of the CPUs base, destroying a few of the CPUs outwards constructions like missile turrets, before he can fully develop his base and launch the final attack.
 * In order to keep the game playable on 8-16 MHz systems, the designers had off-screen units update at about half the rate of those on-screen. This only affected movement, but it resulted in a player being able to move an army much faster if he scrolled the map to keep them in view.
 * Nearly every map in the game had at least one very long interconnected path of rock leading from the player's base to the enemy base. Unfortunately, this led to the practice of "creeping", where players would place concrete all the way up to the enemy base and begin erecting turrets, removing the need for a large component of the gameplay.
 * Because of errors in the code, combat units gained a slight increase in range when placed at certain angles; Rocket launchers attacking from the north or south and one column right or left could out-range Missile Turrets, but from other angles could be easily destroyed by return fire.
 * The Atreides sonic tank attack range is supposed to cover the whole screen, but the range is actually determined by the "Game Speed" setting. When set to "Very Fast" the attack covers the whole screen, but when set to "Very Slow" it only covers about half of the screen.
 * The rocket launchers' range is also affected by the "Game speed": at the "Very slow" setting, the rockets can fire accurately at close targets, while, at higher speed settings, rockets fired on nearby targets go out of control and fly in unpredictable directions.
 * In counter to the above, sandworms' speed isn't affected by "Game speed": they move at the same rate regardless of the setting. This actually makes them very dangerous at lower speeds as they will likely consume your unites before they have a chance to move.
 * Carryalls would pick up damaged units and bring them to a repair center. If every side of this repair center was blocked, the Carryall would return the vehicle to its former position. As long as the unit would only attack buildings, the enemy ignored it.
 * The Ordos deviator changes the loyalty of a targeted unit to yours for a short period of time. If you "deviate" an enemy unit, select it, and then click the Attack or Move button without selecting a target. Eventually, the unit will revert to its original side. However, you will keep the target cursor, and can now select a target. The unit will think it received the command from its own side, and will execute it and continue to do that command until it is completed or the unit takes damage. Common uses of this tactic are to have the "deviated" unit destroy a computer structure or to command an enemy harvester to drive back to your base, where you can destroy it. (Any harvested spice in the enemy harvester when it is destroyed will be placed on the ground.)
 * Furthermore, deviated units ordered to attack houses other than their own will continue to attack them even after the deviation wears off. A deviated Atreides tank ordered to attack a Harkonnen base, for example, will continue to attack the base even after the deviation wears off.  (Fremen are great targets for deviation, since they will always continue to attack whatever they were ordered to attack after the deviation wears off.)
 * When you own a House of IX and capture an Ordos Heavy Factory you can build your own Deviators. However, any targeted units will change to the Ordos side instead of your own. This may be intentional, since a captured Sardaukar Heavy Factory allows construction of both the Atreides Sonic Tank and Harkonnen Devastator, but not the Ordos Deviator.
 * Due to a programming error, the enemy AIs don't produce vehicle assault teams like they were meant to.

Fixed glitches

 * In the earlier versions, the AI turrets did not attack enemy Fremen units, but your own turrets did. This was fixed in a later version.
 * The sandworms technically belonged to the same side as the Fremen. As they were allied with the Atreides, units and turrets from this house would not attack them.
 * In earlier versions of the game, you could place a refinery near a spice pool. The carryall will bring the harverster as soon as you place the refinery. Let the harverster collect spice for at least five seconds and issue a return to refinery command. If the carryall that brought your harvester is still flying near your base, it will pick up the harvester and transport it to your base. The harvester will drop some credits and soon be ready for release. The carryall then takes the harvester back to the field and never leaves the warzone, as it should. Instead, it will work as if you had constructed a carryall. This is very useful early in the game before Carryalls become available for construction.
 * The computer sometimes destroyed your units by building over them, thus causing them to disappear. This was probably because the AI had no way of delaying placement structures after they were built, and thus didn't check whether the space was clear of units first. The Mega Drive version of Dune, and all RTS from Command & Conquer onwards do not allow this - the AI cannot rebuild structures if you block the placement area.
 * In earlier versions House Atreides could command Sandworms, but could order them only to attack units.
 * If you attack an enemy harvester with an infantry unit the harvester will attempt to run it over. In the initial 1.0 version of Dune II the harvester would stop collecting spice once it had crushed the infantry unit, neutralizing it. This was a useful strategy as maps contained limited supply of spice and it was important to prevent the computer from harvesting it all, especially in the later levels. This bug was fixed in the 1.07 version of the game.
 * Saboteurs explode upon reaching their destination with the move command, regardless whether it's an enemy building or a group of your own soldiers. The Mega Drive and Amiga versions fix this by making them only explode upon entering an enemy building.

Trivia

 * Mercenary units (and a few accompanying sound bites) were included in the game code, but never implemented.
 * There is a hacked version of the game known as Super Dune 2, which replaces the three campaigns with new missions for the three non-player-controlled houses; Fremen, Sardaukar and Mercenaries.