Research Tree

Lore & Background

Within the XCOM universe, the research tree represents the collective scientific effort of a covert organisation fighting an alien occupation. Each node is a project—reverse-engineering a Sectoid weapon, synthesising adaptive nanomaterials, or constructing a new wing of headquarters—and the prerequisite links mirror the real dependency between disciplines: you cannot build a plasma cannon before you understand the containment field, and you cannot train a psionic before the lab exists to house them. The tree is deliberately fixed in Enemy Unknown and Enemy Within, reflecting the narrative logic that alien technology follows a single, discoverable path. The player's role is not to invent but to sequence: deciding whether to prioritise a new rifle or a new hangar bay, knowing that every point spent on one branch delays the other. In XCOM 2, the tree was loosened to better suit a longer, less linear campaign, but the underlying principle remains—knowledge is a finite resource, and the organisation can only pursue so many threads at once. Scientists in EU/EW are generic, unnamed personnel, not individual named characters; a base raid may kill soldiers but does not directly affect research personnel in that way, making the research tree a strategic puzzle rather than a narrative of personal loss.

In Their Own Story

The lab hummed at 2 a.m., the only light in a corridor of concrete and blinking status panels. Dr. Somewhere above, in the hangar, a young trooper was still firing the old ballistic sidearm, still flinching at the recoil. "You could pull me to the Psionic Lab," she said, not turning around. "They need a third scientist tonight."

The Director's silhouette stood in the doorway. "And the plating?"

"Two more days. Three, if the Sectoid data from the last raid is clean."

He was quiet for a long moment. Outside, the wind pressed against the blast shutters. "Run the plating. The psionics can wait a cycle."

Okafor nodded, already typing the next allocation. The tree on her screen shifted, one branch brightening, another dimming to grey. Somewhere in that grey, a future weapon waited for a future hand to build it.

Reader's Guide

In XCOM: Enemy Unknown and Enemy Within, the Research Tree is a fixed branching diagram. Each project lists one or more prerequisite projects that must be completed first. Research points are generated each turn by labs (scaled to the number of scientists assigned) and are also awarded when alien corpses and data discs are processed after combat. The player selects which eligible projects to pursue; multiple projects can be in progress simultaneously, limited by the number of active labs. Completed projects permanently unlock their reward—a new weapon, an armour upgrade, a base module, or a special ability—into the tactical roster. XCOM 2 restructured the system. Research is still generated by labs, but the tree became more flexible, and science is also earned through specific mission objectives rather than solely from combat loot. The prerequisite structure remains, but the player has greater freedom in choosing which branches to develop, and the pacing of unlocks was adjusted to suit the game's longer, more open-ended campaign. Strategically, the tree forces a constant trade-off: investing in offensive firepower accelerates individual fights, while base modules compound over time. Because scientists are a finite, vulnerable resource, the player must balance lab allocation against other base needs. The tree also gates endgame content—certain late-game technologies are reachable only after a long chain of prerequisites, making early research choices a de facto campaign strategy.

Did You Know?

• In XCOM: Enemy Unknown the full tree is not visible from the start; only initial nodes are shown, and later nodes become visible after prerequisite research is completed.
• Researching a base module in Enemy Unknown does not automatically add a new room; it unlocks the ability to excavate and build that room, requiring additional resources and time.
• In XCOM 2 the research system was redesigned to be less linear, giving the player more agency over which technology branches to develop and in what order.
• In XCOM: Enemy Unknown and Enemy Within, scientists are generic, unnamed personnel, not individual named characters; they cannot be killed in a base raid.
• In XCOM: Enemy Unknown and Enemy Within, labs provide a flat +20% bonus to research speed, not a multiplicative effect on research points generated by scientists.