By far, the largest difference between Master of Orion and Starbase Orion is tactical combat. Tactical battles in Starbase Orion are, basically, real-time simulations. When two or more hostile fleets meet at a star system, the players set battle behavior for each ship or ship type. Behavior includes maneuvering (close to short-range, maintain medium range, maintain long range, stay close, evade, retreat), targeting (largest, smallest, weakest), primary target and primary escort. Beyond that, players have no effect on the battle, the results of which are displayed at the start of the next turn. Already knowing the final result, the players may watch the battle simulation. A battle may last more than one turn if not all ships of either side have been destroyed or if reinforcements have arrived. All non-missile weapons always hit (unless the target ship is either commanded by Eesathu or has Auxiliary Thrusters), so firepower is usually the deciding factor. This was likely done to speed up multiplayer games, as turn-based tactical combat between large fleets can take a long time.
Planetary improvements are done in the style of Master of Orion II, although each planet has a limited number of building slots (depending on planet size). Each improvement requires a different number of slots. Most require 1. One requires 2. Orbital structures require 0. Unlike MoO, only one starbase may be built per system, and it protects the whole system. Certain structures are improved versions of existing ones and do not take up extra space (e.g. Trade Port II replaces Trade Port I). The number of slots may be increased after researching and building certain improvements.
Research is divided into three categories: astrophysics, civic, and military. However, it's not always clear how they are subdivided, as starbases are placed in the astrophysics category despite being military structures. Each technology has a colored indicator by it, showing how many technologies can be researched in this category before it disappears. Red means that, if the player chooses to research a different technology from this category, this one will be lost, although it may re-appear later. Yellow means you are 2 technologies away. Green means 3.
Ship types are identical to Master of Orion II, except Doomstars are called Mammoths. As before, Titans and Mammoths need to be researched. However, Battleships need to be researched as well. Freighters are not built separately, but extra food is automatically transported between non-blockaded colonies at a cost. Extra food that is not used is sold for profit. Instead of size, each ship type has a certain number of weapon slots and a certain number of equipment slots. The number can be increased through research. For example, Frigates can initially fit only one weapon and two pieces of equipment, but can be increased to three weapons and four pieces of equipment. Equipment can be faster engines, larger fuel tank, thicker armor, shield generators, etc. Refitting ships is not possible, but existing ships can be scrapped either for cash or to speed up production on a colony in the same system. Thus, players can imagine that a scrapped cruiser whose resources are applied to the production of a new cruiser is actually being refitted. Since ships don't gain experience in Starbase Orion, there is really no benefit to keeping existing ships versus brand-new ones.
There are only six types of weapons, although each type of weapon has three stages of improvement unlocked through research which increase damage and reduce cost. Lasers are, usually, the earliest to be researched: weak damage decreased with distance, cheap building cost, double damage against shields but half against structure. Gauss turrets are close-range weapons that completely ignore armor but are terrible against shields. Plasma turrets are for extremely long-range fights (i.e. damage increases with range) and are more effective against shields, but are fairly weak and have a reduced effect on armor. Nuclear missiles have long range but fire once every three battle turns and do less damage to shields and armor but have a bonus against structure; damage is not reduced by range. Photon torpedoes also fire once per three turns and are less effective against armor, but travel faster, do significantly more damage, especially against shields, and are more resistant to point-defense. Missiles and torpedoes can be countered with point-defense and ECM systems. Ion pulse cannons are late-game weapons that are more effective against structure than shields or armor; however, the weapon does more damage to structure if the enemy has shields by overloading the shields. Unlike other weapon types, ion pulse cannons can only be mounted on battleships, titans, mammoths, and starbases.
Military and colony leaders can be hired at auctions. Auctions last for several turns but can be extended due to fierce bidding. A player is initially limited to 1 leader total, although that number can be increased to 3 and 5 with research. Upon reaching the limit, the player may not even place a bid on any new leader. Leaders are pretty unique in their effects on planets, ships, fleets, or the whole empire. The "per turn" cost of supporting a leader is proportional to the final hiring price. Leaders do not gain experience. "Killed" leaders reappear at the auction in a turn or two. See the character page for information on the races and leaders.
Unlike Master of Orion II, fleets underway may not be redirected. The only exception is for a race that hires the colony leader Morph, although that feature is known to be buggy (which is Hand Waved as a side effect of an interrupted warp jump).
In 2013, an attempt was made by Chimera to raise funds via Kickstarter to port the game to Android, PC, and Mac, but the project fell far short of the goal and was scrapped. There are mentions of a sequel in development, but no details have been revealed.
The game contains examples of the following tropes:
- Arbitrary Headcount Limit: Each player is limited to 1 leader from the get-go, although there is a racial trait that raises the initial cap to 2 (the final cap remains the same). This number can be raised to 5 with research but no higher. Likely, this is done to prevent a wealthy player from unbalancing the game further by hiring all possible leaders. Ship command points are a soft version of this trope. More ships can be built than the points allow, but they become a drain on the economy. Alternatively, the number of points can be increased by colonizing/conquering more planets, building starbases, or hiring Morph.
- Arbitrary Maximum Range: All weapons have a maximum range, beyond which they won't fire. After that, damage typically decreases with distance to target. Exceptions included missiles and torpedoes (same damage regardless of distance), as well as plasma cannons (damage increases with range).
- Artificial Stupidity: Given the developers' focus on multiplayer, it's not surprising that the game's early AI was, shall we say, not up to par. Computer players would consistently make stupid mistakes, such as only ever building one large fleet. After that was destroyed, they would constantly send single ships at the enemy instead of massing them into a fleet first. Additionally, they would keep sending unarmed transports or colony ships at planets that are obviously protected, or only include one transport ship with its fleet, even though a single transport's worth of marines can't capture a world with even one defending marine present. Much of this behavior has since been corrected, although the sending-one-ship-at-a-time problem does, occasionally, show up. There is also a rare case of the enemy sending a large fleet of cruisers and destroyers... with absolutely no weapons. In addition, an AI will almost never build anything other than cruisers and destroyers, with maybe an occasional battleship or two. No Titans or Mammoths. The only frigate an AI player is likely to have is the original scout. Apparently, the developers figured that cost-wise, a mix of cruisers and destroyers is the best thing to have.
- Ascended Glitch: When leaders were first introduced, Morph's ability to redirect fleets in transit was buggy. Redirected ships would sometimes randomly appear elsewhere in the galaxy or join other fleets. Instead of fixing it, the developers simply added a blurb in Morph's description that this ability can have unintended side effects, thus making it seem as if they intended for this to happen all along.
- Attack! Attack! Attack!: Retreating from a battle wasn't an option in the early version of the game but was added later. When Mortis Wretch is present in a battle, no ship can retreat until his ship is destroyed. Still, no AI player will ever retreat from a battle.
- The Battlestar: Any ship to which Captain Jack Gentry is assigned is equipped with Raider Launch Bays that launches several Gauss turret-armed Frigates during battle. Gorzhons's ship is equipped with Dark Matter Incubators, periodically creating Dark Matter units. The Hatchery would be this if it had any weapons.
- Binary Suns: Planets in binary systems get farming bonuses due to increased solar radiation.
- The Computer Is a Cheating Bastard: In early versions of the game, Artificial Stupidity was everpresent. In order to give the computer players a chance, the developers have allowed them to have any number of ships regardless of command points or to have those ships pretty much spawn above planets that don't have the industrial capability to build them. In later versions, this became an option alongside AI difficulty level. Should the option be turned off, the computer players would not cheat (as far as we know).
- Deflector Shield: Different-strength shield generators can be placed on ships. Different weapons affect shields to a different extent. Nebulae cause shields to fail, unless an additional device is mounted on a ship. Ion pulse cannons can overload active shields, which causes additional damage to structure, even though they do little damage to shields themselves, making it possible to destroy a ship without fully knocking down its shields.
- Design-It-Yourself Equipment: You can customize ship and starbase weapons and systems and save them as classes, similar to MoO. However, unlike MoO, ships/starbases have a certain number of weapon and system slots (instead of going by mass). These can be increased with Warlord (weapons) and Pacifist (systems) research by a max of 2 each. Each weapon/system has a cost that adds to the cost of the ship. Starbases cost the same no matter what weapons and systems they contain (existing starbases are automatically updated to match the new designs). Most systems have stackable effects, but their costs double for each additional "stacked" system. Unlike starbases, existing ships are not automatically updated to match the new specs. Since refitting ships is not possible in Starbase Orion, the only alternative is to scrap the existing ship at a planet with a starbase and apply the production to the construction of a new ship. Since ships don't earn experience, there's no benefit for keeping old ships anyway.
- Energy Weapon: Laser beams are the earliest weapons researched. They do weak damage that decreases with range. Double damage against shields but half against structure. Point Defense Systems also use lasers to shoot down missiles and torpedoes, although those are automatic. Additionally, Ion pulse cannons are not lasers but look very much like them and have an added bonus of doing more damage to structure if enemy shields are engaged.
- Giant Space Flea from Nowhere: Like Master of Orion, important worlds are protected by space monsters such as Dark Matter (black clumps that move fast and are armed with Gauss turrets), Amoebae (battleship-sized monsters with lasers), and Crystals (Titan-sized creatures with Ion pulse cannons). With the introduction of Leaders, it's clear that they were created by the Gorzhons.
- Hitscan: Since battles are only simulations, the outcome is already known by the time players view them. Additionally, all weapons except for nuclear missiles and photon torpedoes always hit (a ship commanded by Eesathu is an exception, as well as ships equipped with Auxiliary Thrusters), and the result is registered on the shield/armor/structure scale even before the animation of the firing finishes playing. As such, it's not uncommon for an enemy ships to blow up before the shots that were supposed to destroy it even arrive. This is the same for missiles and torpedoes that the game engine has determined will hit (also before they are even launched).
- Hyperspeed Escape: Two of the behaviors that can be set prior to the battle are "Escape" and "Disengage". Originally, neither option was available. Then "Escape" was added, allowing a ship (or a fleet) to maneuver for a bit, moving away from the enemy. If the ships survive, then they flee the battle and set course for the nearest friendly colony. The recently-added "Disengage" option results in a much more ordered, slow retreat, after which the fleet remains in the system and may be given further orders.
- Imported Alien Phlebotinum: There are several ways of getting new tech without researching it. A random event may grant you a free tech on scouting an unknown system (according to the game text, from a derelict ship). Colonizing a planet with ancient ruins also nets you a new tech the following turn. You can send spies to an enemy empire and set their focus to steal a technology from a specific branch, although their success depends on many factors. You may also demand a piece of technology from another empire, but they're likely to refuse. Additionally, another player may simply give you a technology, but don't hold your breath. Finally, if you employ the Rogue Captain, he can salvage destroyed enemy ship after a victorious battle in which he's present and may even recover a usable piece of military tech.
- Macross Missile Massacre: Averted. Prior to v1.2.6, missiles and torpedoes had extremely limited ammo, which could be increased by a certain amount through several means. With the new update, the ammo cap is removed, but the two weapons now fire once every three battle turns. It's possible to speed up the rate to every other turn with a piece of equipment, but it's still far cry from saturating space with missiles/torpedoes. The only way to achieve this effect is to have dozens of ships all armed exclusively with missiles/torpedoes.
- Magnetic Weapon: The Gauss turret fires a stream of armor-piercing projectiles at the enemy, although they are nearly useless against shields.
- More Dakka: The idea behind the Gauss turret.
- Obvious Rule Patch: The game's battle mechanic means that a large enemy fleet can be almost indefinitely held at a system by simply sending a Frigate or two to engage them every turn. The game counts them as reinforcements and, thus, doesn't end the battle (although nothing prevents the large fleet from retreating). After the use of this tactic has annoyed a good number of players, the developers have made sure that a small force (a few Frigates) will automatically be destroyed when confronted with a large fleet.
- Older Is Better: Averted with the Crystals. The ones present in several systems are actually weaker than the ones that are randomly spawned by the Hatchery that a player can build after recruiting the Gorzhons. Apparently, the Gorzhons have made some improvements over time, although spawned Dark Matter and Amoebae are identical to their older versions.
- One-Federation Limit: Every political entity named in the race and leader descriptions has a unique name.
- Humans - the Confederacy.
- Isather - the Isather Dominion.
- Draske - The Draske Hegemony.
- Cyban - the Community of Cybans.
- Vass - the Vass Collective.
- Harge - the Harge Commune (a colony leader is a Harge). A client race of the Draske Hegemony.
- Felinoids - the Gnactic Space Federation (a military leader is a Felinoid). A client race of the Draske Hegemony.
- Plasma Cannon: Plasma turrets are long-range weapons. They are unique in that they do more damage at their extreme range rather than up-close. The game explains this as the fact that the plasma cloud expands as it travels, although, realistically, this should reduce damage. They are also more effective against shields than other weapons, at least as far as its base damage multiplier. It's also the only non-missile weapon that can't be dodged by a ship with Auxiliary Thrusters.
- Point Defenseless: Ships or stations equipped with Point Defense Systems can destroy enemy missiles and torpedoes with Frickin' Laser Beams, although the system can be overwhelmed by multiple launchers. This, in turn, can be countered by equipping a ship/station with multiple PD systems. ECMs can also be used to counter missiles and torpedoes, causing 30% of them to miss.
- Orbital Bombardment: Unlike MoO, it's not easy for ships to rain Death from Above on colonies. For one, planets are not present in battles. Outside of battles, bombarding a planet requires researching the Orbital Bombardment Package and equipping ships with it. Alternatively, assigning Mortis Wretch to a ship equips it with the same.
- Our Wormholes Are Different: The wormholes are treated the same as in MoO. They are randomly-generated at the start of the game and connect remote systems, allowing one-turn travel between them.
- Portal Network: Like MoO, you can research and build warp gates in systems. Warp Gate I permits ships traveling between them to go much faster. Warp Gate II permits one-turn travel between them. Unlike Master of Orion II, gates need to be built by colonies.
- Precursors: The Gorzhons were the masters of the galaxy tens of thousands of years ago. Then they disappeared, leaving behind ruins and space monsters. Now several of them have returned and are willing to work with the younger civilizations in preparation for their Great Return.
- Space Clouds: Nebulae prevent shields from working, although an additional device can be installed on ships to negate this effect. Additionally, research may enable the construction of an artificial nebula surrounding a system.
- Space Elevator: Building these in colonies speeds up ship construction. Strangely, does not affect the construction of any orbital structure (e.g. starbase, weather satellite, orbital lab).
- Space Station: Starbases protect systems from attacks and repair friendly fleets in the system. Higher-level starbases have more structure and armor points and more weapon and equipment slots. Fve Bgeeep's Burrow is a unique starbase to which any other starbase is upgraded to when Governor Fve Bgeeep is in the system (the starbase reverts to its original state if he leaves); it's way more powerful than even a level-3 starbase and takes an armada to destroy.
- Stealth in Space: Unlike Master of Orion, there are no cloaking devices in Starbase Orion. The closest thing is Tyrrhenius's ability to hide his fleet while in transit. Also, any friendly fleet in Magistrate X's system is also invisible to the enemy. It's possible to research and build the Deep Space Jammer, but this piece of equipment takes up 6 slots on a ship and only prevents the enemy from knowing the composition of the fleet.
- Take That!: The description of the Baby Boomers racial trait pokes fun at abstinence-only sex ed.
- Terraforming: A repeating planetary project that "upgrades" a planet to the next more habitable level until Terran. After that, you have to use the Gaia Device to get to the Gaia level. More habitable planets have higher population caps and base morale, although the number of building slots is only determined by the planet's size and can only be increased by certain techs.
- Unexplained Recovery: When a ship or a colony with a leader are destroyed, the leader does not die. Instead, he/she/it shows up at the leader auction the next turn. This is likely done due to the significantly smaller number of leaders in Starbase Orion compared to MoO 2
- Violence is the Only Option: Diplomacy was non-existent in the early versions of the game. Thus, destroying all enemies was the only way to win. However, even with the addition of diplomacy, destruction of all other factions is pretty much expected. The only victory options are the destruction of everyone else or an allied victory.
- Wave-Motion Gun: Any ship to which Captain Jack Gentry is assigned is additionally armed with a Stellar Burst Cannon, a long-range weapon devastating against any type of defense.