// 04 — Research
Technology
Technology
Tree
// X-COM Tech Tab
// Alien Tech Tab
// Screenshots from RimWorld 1.5 research screen
The alien threat arrives on the Rim. Rebuild the X-COM program. Research extraterrestrial technology. Defend humanity.
X-Rim: Enemy Unknown is a total-conversion-style content mod that brings the legendary X-COM universe into RimWorld. Face extraterrestrial threats, research alien technologies, build a response program from the ground up, and equip your colonists with weapons that range from precision ballistic arms to plasma-based alien ordnance.
Unlock the X-COM research tree by establishing a dedicated research lab. Progress through two parallel technology tracks — human-developed tactical tech and reverse-engineered alien science — each gated behind appropriate facilities and research prerequisites.
Faithful to the 1994 original X-COM: UFO Defense. Weapon names, progression curve, and technology logic mirror the classic game. Balance is tuned for RimWorld mid-to-late game without trivializing vanilla content. XML-first implementation with C# only where XML is insufficient.
Structured around a two-tab research tree: X-Com Tech for human-engineered equipment, and Alien Tech for reverse-engineered extraterrestrial systems. Advanced alien research requires the dedicated Alien Analyser facility.
RimWorld 1.5. No DLC required. No external mod dependencies. Compatible with most content mods — the research tree operates on its own branch without patching vanilla research. Load order is flexible.
Four dedicated X-COM facilities: Laboratory, Workshop, Nanite Printer, and Alien Analyser. Each unlocks further tech branches.
XCOM Pistol and XCOM Rifle — precision ballistic sidearm and long-range assault rifle with custom projectiles and sounds.
Heavy Cannon and Autocannon in three ammunition variants: Armor Piercing, High Explosive, and Incendiary.
Mini-Turret and Autocannon Turret in all three ammo types (AP/HE/I). Custom icon set per variant, 10 textures total.
Specialized barrel types: Reinforced Barrel (AP/HE/I), Laser Focus Array, and Plasma Containment Core as crafting resources.
Original weapon sound effects including pistol/rifle fire, cannon blast, UFO impact, and stun rod zap — sourced from the original X-COM.
| Weapon | Type | Research Gate | Ammo / Variants | Range | Burst |
|---|---|---|---|---|---|
| XCOM Pistol | Sidearm | XCOM_Tech_Pistol | Pistol Bullet | 23.9 | 2 |
| XCOM Rifle | Assault | XCOM_Tech_Rifle | Rifle Bullet | 30.233 | 2 |
| Heavy Cannon | Heavy | XCOM_Tech_HeavyCannon | APHEI | 37.2 | 1 |
| Autocannon | Heavy | XCOM_Tech_HeavyCannon | APHEI | 27.567 | 6 |
| Mini-Turret | Turret | XCOM_Tech_DefenseTurret | APHEI | 34.6 | 1 |
| Autocannon Turret | Turret | XCOM_Tech_DefenseTurret | APHEI | 39.4 | 2 |
| Laser Pistol | Sidearm | XCOM_Tech_LaserPistol | Small Laser Charge | 28.49 | 1 |
| Laser Rifle | Assault | XCOM_Tech_LaserRifle | Medium Laser Charge | 40.59 | 1 |
| Heavy Laser | Heavy | XCOM_Tech_LaserCannon | Heavy Laser Charge | 49.4 | 1 |
| Laser Mini-Turret | Turret | XCOM_Tech_LaserDefence | Medium Laser Charge | 38.1 | 1 |
| Laser Cannon Turret | Turret | XCOM_Tech_LaserDefence | Heavy Laser Charge | 43.3 | 2 |
| Weapon | Type | Research Gate | Ammo / Variants | Range | Burst |
|---|---|---|---|---|---|
| Plasma Pistol | Sidearm | XCOM_Tech_PlasmaPistol | Small Plasma Charge | 26.195 | 1 |
| Plasma Rifle | Assault | XCOM_Tech_PlasmaRifle | Medium Plasma Charge | 35.412 | 1 |
| Heavy Plasma | Heavy | XCOM_Tech_HeavyPlasma | Heavy Plasma Charge | 43.3 | 1 |
| Plasma Mini-Turret | Turret | XCOM_Tech_PlasmaDefence | Medium Plasma Charge | 35.5 | 1 |
| Plasma Cannon Turret | Turret | XCOM_Tech_PlasmaDefence | Heavy Plasma Charge | 40.4 | 2 |
| Rocket Launcher | Heavy Explosion | - | HEI | - | - |
| Missile Turret | Turret | - | HE | — | — |
| Blaster Launcher | Heavy Explosion | - | HE | - | - |
| Blaster Turret | Turret | - | HE | - | - |
| Small Launcher | Non-lethal weapon | - | ST | - | - |
// Screenshots from RimWorld 1.5 research screen
A single unified alien faction — XCOM_Faction_Aliens — with permanent enemy status. Five distinct races, each deployed in mission-specific group compositions. Thirty PawnKindDef entries across six military ranks. Killing commanders shifts the political landscape.
| Rank | Combat | Special | Kill Reward | Psionic Races |
|---|---|---|---|---|
| Soldier | Strong melee + ranged | — | — | — |
| Terrorist | Average combat, high speed | Psionic Panic attack | — | Sectoid, Ethereal |
| Navigator | Weak fighter | High Intellectual skill — live capture unlocks research | — | — |
| Medic | Weak fighter | High Medicine skill, treats wounded in combat | — | — |
| Commander | Very strong combat | Psionic Panic + Mind Control | +5 all factions | Sectoid, Ethereal |
| Leader | Elite combat | Psionic Panic + Mind Control (multi-target) | +10 all factions | Sectoid, Ethereal |
Cryssalid bite → HediffDef "Chryssalid Infection" with countdown timer.
Timer expires → pawn dies, Zombie pawn spawns.
Zombie after N ticks → dies, new Cryssalid spawns on location.
The single most dangerous biological threat. Carried by Snakeman raiding parties.
One uncontained infection can cascade through the entire colony.
Aliens don't reproduce naturally. Abduction raids exist to capture colonists.
XCOM_AlienPod_Embryo — building on alien base. Captured colonist is assigned, timer counts down, pawn is converted into an alien of the corresponding race.
Rescue mission: destroy the pod before the timer expires to save the captive.
Aliens don't eat human food. Their nutrition comes from processed human or bovine meat — a direct nod to the original X-COM's imagery.
XCOM_AlienNutrition — processed meat ration, consumable only by aliens (RaceDef foodType = Meat). Alien bases produce it from cattle or human remains.
Terror Missions may deploy cattle as civilian targets — a deliberate lore reference.
Tanks and hover platforms are Pawns, not turrets — mobile combat units produced in the Platform Assembler, analogous to RimWorld's mechanoid gestator.
Each HWP type has a global count limit via PlatformLimitExtension. Tracked chassis: max 3 per type. Hover chassis: max 2. Weapon loadout is set at production via barrel component in recipe.
Faithful to the original X-COM, the alien campaign is not passive. Extraterrestrial forces pursue their own agenda — probing, terrorizing, and infiltrating — while your colony builds its response program. Below are the planned mission types for the alien faction AI.
Alien forces land and abduct colonists from the map. Uncontested abductions increase alien activity score. Successfully repelled raids yield alien corpses and potential salvage.
Alien forces attack a settlement with the goal of maximizing civilian casualties. High-intensity combat encounter. Failure results in significant morale and faction standing penalties.
Small scout ship enters the map to gather data on your colony layout and defenses. If not intercepted, alien forces gain tactical intelligence — future raids arrive with better positioning.
Alien logistics ship delivers reinforcements and resources to existing ground forces. Destroying the supply ship before unloading denies the enemy reinforcement and can yield Elerium salvage.
Alien agents attempt to establish a covert presence within or near your colony. Undetected infiltration accelerates escalation tier. Requires Mind Shield or active psionic defense to counter.
If alien activity score goes unchecked, extraterrestrial forces attempt to establish a permanent base of operations on the planet. Assaulting and destroying it is a major mid-game objective.
This project utilizes the RimWorld XML Toolkit, which provides specialized tools for static analysis of XML graphs. For more information on the technical implementation, see Building IntelliJ Plugins for Complex XML Systems.