Info (OpenXcom)

What is X-COM?

Haha you're kidding right?

X-Com is a simulation of an alien invasion of earth. It is composed of two parts.

In part 1, you are focused on globe-level activities: Tracking UFO actions around the world (possibly shooting them down, or sending troops to the sites of ship landings), keeping governments happy with your actions, getting funding money from various governments, and spending it on soldiers and equipment.

In part 2, you are in a turn-based, tactical, grid-based combat simulation, with fog-of-war; your goal is generally to defeat (capture or kill) the aliens in that battle. More accurately, you are scored based on a variety of functions (aliens killed, innocent bystanders killed, etc), and your goal is to be positive. It is possible to have to flee but still have positive points (considered a marginal victory -- you might not have stopped the aliens, but you did enough damage that your funding nations will be happy enough).

Most, but not all, of these battles will involve an alien ship, either intact or damaged.

The overall gameplay alternates between globe-level, and single-battlefield level, until either your forces are completely wiped out, or you have defeated the enemy invasion.

What is OpenXcom?

OpenXcom is an open-source clone of the original X-COM, licensed under the GPL and written in C++ / SDL. It was originally founded by SupSuper in February 2009, and has since grown into a small development team surrounded by a very supporting community.

The goal of the project is to bring back the tried and true feel of the original with none of the issues. All the same graphics, sound and gameplay with a brand new codebase written from scratch. This should give it:

• Fixability: Play the game natively without any need for emulators or fancy hacks, with none of the limitations and bugs that plagued the original. No more 80-item-limit, personnel limits, funding overflows, disconnected facilities, broken proximity grenades, floating soldiers, etc.

• Moddability: Tweak the game to your heart's content. Sure the original was pretty good, but maybe you just think it could be that bit better. A nicer base layout, better laser weapons, maybe challenge yourself with a custom game mode, or just put in all the crazy stuff you've always wanted! None of it is hardcoded. See Mods (OpenXcom)

• Flexibility: Port the game to any platform you like, customize it to your liking, or use it to make your own far-fetched remakes. The code is fully documented and open-source so anyone can take a crack at it.

Beyond OXC

You probably want to use OpenXcom with mods. It helps to understand than any mod may have one of 3 distinct engines as a requirement: pure OXC, Nightly or OXCE. They are backward compatible, with some caveats or tinkering. For example, Hybrid Mod (which combines X-COM and TFTD) or X-Com Files require OXCE. There are many mods. Fortunately, it’s not a complete mess. Metadata file included in the new path structure (Nightly and OXCE) allows mods to specify the required version of OXCE, if any, and master ruleset - normally xcom1 or xcom2 (TFTD), but sometimes another mod (which may have its own master ruleset in turn). In the mod setup page of Nightly or OXCE a drop-down list chooses the master, and only mods under that master are displayed - so e.g. if you want X-Com Defence, the list is not cluttered with mods relevant only to TFTD or X-Com Files. See also Installing (OpenXcom).

• Old OXC: the proper, stable release version. Updated approximately once per forever. Has few mods beyond improved resources (such as better sprites or sounds).
• OXC Nightly: as the name implies, it's a development/modding branch regularly compiled from its official repository. Bug fixes can be applied quickly, the rest seems to seep from OXCE very slowly. Specifically, it’s a more stable branch lagging far behind OXCE. It has directory structure reworked and mod metadata file (metadata.yml) is required.
• OpenXcom Extended, aka OXCE: a cutting edge development branch of OpenXcom ahead of Nightly. Many features are moved from hardcoded to available for modding, some new features (accessible via mods). Since it's a very fresh development version, there's some risk that modding markup dialect may change in future.
  • So e.g. Nightly allows shotguns, but the only parameter is number of pellets in a round of ammunition. OXCE treats it as one spread shot, rather than simultaneous shots, and allows to set width and choose distribution of their spread.
  • Grenade functionality is split and customizable. TU costs of all actions with items are adjustable.
    • You can have fuses other than mostly-useless dial from the original game.
    • Items can be primed and un-primed, if configured this way. Mostly applies to grenade type items, but also flares.
    • If you want to acknowledge the unpleasant fact that a demolition charge timer is ticking whether someone holds it tight or not, give it "isExplodingInHands: true" and it can go off while in equipment.
  • For weapons, ammunition expended per shot in each firing mode is adjustable.
    • Firing mode strings can be customized, too. A double-barreled shotgun is just a shotgun with "autofire" mode set to 2 shots and renamed.
    • Damage modes are customizable. A specific weapon can be made to inflict extra damage to armor before hit is resolved normally, have custom rate of damage to armor, or have relevant resistance lowered or increased against it. If you want High Explosive to breach UFO walls, in OXC this can be done by setting power to 200 (that's indeed what standard mod XcomUtil High Explosive Damage does, along with limiting blast radius to 10). In OXCE the same can be accomplished by setting damage rate to tiles at 0.92 for the demolition pack, making its original power 110 sufficient. Likewise with, damage to the items, wounds, and so on. Or make those more erratic.
  • Extra visual effects, with sort-of-particle system. For a demonstration see Hyper & Trajectory mod - speeds of projectiles are set very high, but while you can't see bullets like in the original X-Com, they leave trails of dots.
  • Soldier types. And transformations, with prerequisites. Which can mean anything from special training to cyborgization. X-Com Files has "Martial Arts Training" and "Combat Pilot Training", and some fancy implants.
  • Aircraft may require pilots; their Firing Accuracy affects attacks, Reaction affects defense and Bravery affects approach speed. For a demonstration see Top Gun mod.
  • Craft have shield stats. Craft weapons have types, slots for them have sets of types allowed. Also, "craft weapons" can alter craft stats, thus it's just any upgrade, as allowed by the specific aircraft type. X-Com Files has shield generator, afterburner, maneuver thrusters, extra fuel tanks and radar enhancements.
  • Allows scripting (!), which opens much wider fields for modding.
    • Hatching Chryssalids mod: "Eggs injected by Chryssalids do not kill the soldiers instantly. Eggs can be removed with a Cure" (cure requires some research).
    • X-Com Files Arsenal Additions mod adds things like gas masks. And riot shields that can be wielded or discarded (and fall apart after set amount of damage).

Milestones

The OpenXcom past, present and future development history

Version	Release date	Changes
0.1	October 17th, 2010	Engine Geoscape Basescape
0.2	January 28th, 2011	Language strings Saved games Battlescape Terrain generation Basic units Basic pathfinding, fog of war, lighting
0.3	September 1st, 2011	Items Purchasing Selling Transferring Ufopaedia Options Platform-specific Folders Battlescape Item equipping, firing, throwing Environment: fire, smoke, explosions, damage, kills Unit stats AI Phase 1 (patrol, aggro)
0.4	August 14th, 2012	Research Manufacture Rulesets Battlescape Terror sites Debriefing, scores, experience and skill ups Large units and other alien units Special items (medi-kit, motion sensor, proximity grenade, psi-amp, mind probe, blaster launcher, electroflare)
0.45	November 5, 2012	Ufopaedia Modular rulesets New options Man page / command-line help Logging
0.9	May 7, 2013	Alien Missions Scoring Graphs Victory/Defeat Difficulty levels Geoscape Live alien capture Psionic training Multiple dogfights Battlescape All alien units, items and abilities Alien base, X-Com base and Cydonia missions AI Phase 2 (grenades, blaster launcher, taking cover) Intro/Outro Control Options Advanced Options Display Filters
1.0	June 13, 2014	Everything vanilla Options and extra features Mod support Save backwards compatibility