Tech tree
A nation's chart of researchable vehicles, where each one unlocks the vehicles above it.
Also known as tech trees, research tree, vehicle tree.
Every nation has a tree of branches running from Tier I up to Tier X, split by class. Researching a vehicle unlocks whatever sits above it, so reaching a specific Tier X means grinding the specific line that leads to it.
Branches share vehicles where the historical lines converged, which is why an unusual route through a tree is sometimes cheaper than the obvious one.
Related terms
ResearchSpending a vehicle's experience to unlock its modules and the vehicles that follow it in the tree.ExperienceThe currency earned per battle from damage, spotting, kills, capture and defence, spent on research and crew training.TierA vehicle's rank from I to X, which sets its power level, its battle tier spread and everything about its economy.BlueprintFragments collected from battles that reduce the experience needed to research a specific vehicle, or any vehicle of a nation.