Sins of a Solar Empire

Sins of a Solar Empire is a 2008 science fiction real time strategy video game developed by Ironclad Games and published by Stardock Entertainment for Microsoft Windows operating systems. It is a real time strategy (RTS) game that incorporates some elements from 4X games; its makers describe it as "RT4X". Its first content expansion, titled Entrenchment, was released as a download on February 25, 2009, and its second content expansion, titled Diplomacy, was released as a download on February 9, 2010. A package combining the original game with the first two expansions was released at that time, with the title Sins of a Solar Empire: Trinity. A third expansion, the stand alone Rebellion, was released in June 2012. A sequel to the game, Sins of a Solar Empire II was announced on September 16, 2022.

Sins of a Solar Empire is a space bound real time strategy game in which players control one of three different races: the industrial TEC, the psychic Advent, or the alien Vasari. The playing field is a 3D web of planets and other celestial objects in the orbital plane of one or more stars. The game features a sandbox mode, allowing the player to choose different types of solar systems to unlock achievements. Players can conquer neighboring planets and explore distant star systems in a "massively scaled, fully 3D environment featuring entire galaxies, orbiting planets, clusters of asteroids, space dust and radiant stars." Notably, there is no single player campaign mode, but games can be played against AI opponents offline and other players online. Ironclad Director Blair Fraser asserted that the game's Iron Engine is specially designed with technologies that allow it to handle very large differences in size, scale, and distance.

Sins of a Solar Empire has three main resources to gather: Credits, Metal, and Crystal. Credits are the general currency used by the three races in the game, and are gained by completing missions, collecting bounties, creating a trade network, and taxing planets. Metal is the most common resource in the game, and is gathered by building extractors on metallic asteroids; it is used to construct basic ships and structures. Crystal is the rarest resource, which can be mined from asteroids like Metal; it is used for developing new technologies and building certain advanced ships. A Black Market feature allows players to convert unneeded Metal and Crystal into Credits or vice versa. Selling or buying too much of either resource can cause market prices to rise and fall dramatically. Certain more intangible resources include Supply Points and Capital Ship Crews. Supply Points are used up when ships are purchased, and cannot be accumulated, acting as a population cap for the player's fleet. Capital Ship Crews and Supply Points are both required for the construction of powerful capital ships; regular capital ships require one crew, while the giant titans in the Rebellion expansion require two. A player's maximum Supply Points and Capital Ship Crews can be upgraded, but increased Supply Points require more logistical support, imposing a permanent reduction on the player's income. Players can construct planet based infrastructure upgrades and orbital structures on and around habitable planets that they control. Planetary upgrades grant bonuses such as higher tax incomes, better planetary bombardment resistance and access to more orbital structures. Orbital structures are divided into civilian logistical and military tactical structures. Logistical structures include asteroid mines, ship factories, trade ports, research laboratories and cultural broadcast stations. Tactical structures include orbital weapons platforms, repair centers, strike craft hangars, and superweapons unique to each playable race; for example, the TEC can build the Novalith Cannon, a giant railgun capable of bombarding distant planets.

The Entrenchment micro expansion adds new defensive options. Defensive weapon platforms and strike craft hangars gain researchable special abilities, and all factions gain the ability to deploy proximity detonated space mines. The expansion's most notable aspect is the addition of starbases – immense defensive structures with significant firepower and various special abilities.

There are multiple types of colony supporting planets and asteroids, with the expansions and later downloadable content increasing the available planet types over the years. Habitable worlds range from Earth like Terran planets to frozen Ice planets and water covered Oceanic planets, with some planets possessing random bonuses such as enhanced factories or better defenses. The player can interact directly with planets in several ways, such as creating trade routes, raining destruction from orbit or spreading "culture" via propaganda platforms, which may cause enemy planets to revolt in the player's favor. In addition, there are pirate bases, which are abnormally durable and well defended asteroids that have no resources but provide a boost to tax income. Furthermore, there are several different spatial anomalies (more commonly known as uncolonizable objects) found in the game which serve as obstacles and hazards to all players. These include ice and asteroid fields, which reduce weapon accuracy; gas giants, which can cause dangerous explosions if a ship is destroyed nearby; stars, which allow for interstellar jumps but have large gravity wells that are slow to traverse; and various forms of space junk, which do not affect ships directly. Wormholes link some systems, and once the necessary technology has been researched, they can be utilized for instant travel. In addition, DLCs have added traveling hazards such as plasma storms, random rebellions, economic downturns and coronal mass ejections. Neutral forces, known as militias, guard and may own colonizable planets not occupied at the start by any of the players. Their forces are an assortment of TEC frigates, cruisers and defensive structures. They do not venture outside the gravity well, but will attack anything owned by non militia forces that enter their gravity well. Pairs of pirate ships sometimes similarly "guard" uncolonizable gravity wells.

The diplomacy options of the original game allow players to forge and break alliances and place bounties on their enemies or allies (depending on the game setting) without anybody knowing who placed it. Players can trade resources, establish trade routes between empires, manipulate the commodities market to hinder enemies by utilizing supply and demand, and issue optional "missions" to allies. On November 16, 2011, Sins of a Solar Empire: Trinity was made available for purchase on Steam.

Sins of a Solar Empires Iron Engine offers size and scale technologies that deliver large stars and planets next to comparably small orbital structures, starships and strike craft. The engine features bump mapping on planets and ships, specular lighting, dynamic fractal generation for stars and clouds, and bloom.

Sins of a Solar Empire includes various customization features, among them a level editor that allows players to generate maps for both single and multiplayer use by setting their general properties. Matches can also be recorded and watched, and the game supports custom modifications. Ironclad Games maintains a collection of user created works of all three kinds. The developer has also released the editor used to create the game's scenarios and a set of the development tools. Through the use of this editor, the player can dictate the number of star systems in their game, the number of planets orbiting each star system, and various other options. Lastly, the game keeps track of a variety of achievements, some of which are triggered by ordinary gameplay actions (such as winning as a specific race or collecting enough resources), or by winning with voluntary restrictions (such as without building capital ships, frigates, cruisers, or strike craft).

Ironclad has released three main expansions, which are available on Ironclad's website and Stardock's digital distribution service, Impulse. In addition, the base game and the first two expansions are available in a combination package entitled Sins of a Solar Empire: Trinity. The expansion includes new weapon upgrades and defense platforms, including modular starbases. Originally scheduled for November 18, 2008, it was released on February 25, 2009.

On August 26, 2009, the second expansion was announced. Diplomacy expands the diplomatic element of the game, allowing players more control over alliances and making diplomatic victory possible, as well as offering incentives for peace and cooperation including pacts which provide economic, research, and military bonuses between factions. The opponent AI, pacing and number of game scenarios are also improved. Diplomacy was released on February 9, 2010; the Sins of a Solar Empire: Trinity combination package was also released on the same day. and includes all previously released content. The expansion uses Valve's Steam to download and install updates. The British video game developer Rebellion Developments has been opposing the use of "Rebellion" in the name of the game since 2012 due to trademark law. In November 2018, the game was released as a free download on the Humble Bundle store. Players could redeem the full game at no cost within a timed window. The user was then able to access a Steam activation key to access the game on the platform.

Four downloadable content packs have been released for Rebellion. Forbidden Worlds was released on June 5, 2013, and adds four new planet types and new colonization options. Stellar Phenomena was released on November 6, 2013, and adds interstellar hazards such as black holes, pulsars, coronal mass ejections and neutron stars, which have various impacts on combat and exploration. Outlaw Sectors was released on June 22, 2016, and focuses on Pirates, Black Markets, and Planetary Militias NPC factions that can assist the player in conquering their enemies. Minor Factions was released on December 17, 2018, and included 15 AI controlled minor factions, each offering assistance and unique services to players, if diplomatic relations are established.

A sequel to the game, Sins of a Solar Empire II was teased by Ironclad Games on September 16, 2022. The developers called the initial phase a "technical preview", promoting Ironclad's new Iron Engine. Ironclad Games added multiplayer to its Early Access preview in February 2023, with promises to add further factions throughout the year.

In September 2008, Stardock's CEO, Brad Wardell, stated that Sins of a Solar Empire had sold over 500,000 units, with 100,000 of those being download sales, on a development budget of less than $1,000,000. The game sold 200,000 copies in its first month of release alone. The 2012 Rebellion expansion sold over 100,000 digital copies in its first month of release, setting a Stardock sales record for digital retail.