Traditions

The tradition system is the backbone of your long-term development path in Stellaris. Each tree has 5 traditions plus a bonus for adopting it and a bigger bonus for finishing it — and with 22 trees total but only 7 slots per empire, which ones you pick is a real strategic commitment, not just a formality.

The trees that matter most for opening choices

You won’t have room for all 22, so it’s worth knowing what a handful of the most commonly-prioritized trees actually do:

• Expansion: directly supports early territory grabs — a near-default early pick for most builds.
• Discovery: boosts exploration and research-adjacent bonuses.
• Diplomacy: strengthens external relations and federation-adjacent play — more valuable if you’re leaning into a cooperative or trade-focused build.
• Supremacy: focused specifically on fleets and armies — available to every empire, and the one to prioritize if you’re heading into a war-focused or crisis-prep phase.
• Prosperity: broad empire-wide economic bonuses — a solid generalist pick if you’re not sure what else to take.

This is far from the full list — Adaptability/Versatility, Harmony/Synchronicity, Commerce/Logistics, Domination, Enmity, Fortification, Politics, Subterfuge, Aptitude, Statecraft, Archivism, and Domestication are also real trees, alongside the ascension-specific trees (Cybernetics, Synthetics, Psionics, Biological Ascension, Machine Ascension) tied to your chosen ascension path.

Several of those 22 come in paired variants that swap based on empire type rather than competing for two separate slots: Adaptability is available to regular empires while Machine Intelligences get Versatility instead, individualist empires get Harmony while Gestalt Consciousnesses get Synchronicity, and Commerce swaps to Logistics for gestalts. The variants fill the same structural niche with re-flavored bonuses, so don’t read them as extra options — just evaluate the version your empire actually gets.

The five ascension trees are their own category: they’re mutually exclusive (committing to one ascension path locks out the others for the whole run), and each is gated behind both a technology and an ascension perk or origin. Cybernetics needs the relevant cybernetics technology plus The Flesh is Weak (or Organo-Machine Interfacing), Synthetics needs Artificial Administration plus Synthetic Evolution (or the Synthetic Fertility origin), and Psionics needs Psionic Theory plus Mind Over Matter (or the Teachers of the Shroud origin). The biological and machine paths were rebuilt by recent DLC — with BioGenesis, biological ascension runs through the Biomorphosis situation and branches into the Cloning, Mutation, and Purity trees (without BioGenesis you get the Genetics tree), while The Machine Age splits machine ascension into Modularity, Nanotech, and Virtuality. Budget one of your 7 tree slots for your intended ascension path from game start, because that tree is effectively pre-committed.

Tradition cost scales as you unlock more

Each new tradition costs more than the last — the formula factors in both how many traditions you’ve already unlocked and your current empire size. In practice, this means tradition point efficiency gets more expensive over time, so front-loading your most valuable picks earlier in the game gets more value per point than spreading them out.

The exact curve is worth understanding. Base cost starts at 300 unity and grows with roughly the 1.8 power of how many traditions you already hold — and both the adoption and finisher effects count as traditions for that math, so opening a tree adds 1 to your count while taking its fifth tradition adds 2 (the tradition itself plus the finisher). On top of that, every point of empire size above 100 adds another 0.2% to the cost, which is why wide empires feel tradition-starved unless they actively manage sprawl. Two practical consequences: adoption bonuses are never “cheap filler,” since each one raises the price of everything you take after it, and keeping empire size lean works out to a unity discount on your entire tradition plan.

How it connects to Ascension Perks

Completing a full tree unlocks a slot for an Ascension Perk — which means your tree order directly determines how early you unlock key perks, and with only 7 of 22 trees available per game, tree selection and ascension perk planning should really be thought through together rather than one at a time.

You can hold up to 8 ascension perks in total: one slot per completed tree (7 at most) plus one more from the Ascension Theory technology. Since only a finished tree grants a slot, a half-completed sixth tree is worth zero perk slots — always run a tree to completion before opening the next one, unless you’re deliberately sniping a single adoption bonus and accepting the cost increase.

Common mistakes

• Spreading picks too thin. Adopting four or five trees and finishing none leaves you with barely any ascension perk slots deep into the mid-game. Finish trees one at a time.
• Ignoring empire size. Above 100 size, every point inflates tradition costs by 0.2%. Unmanaged sprawl quietly taxes every future pick.
• Treating adoption as free. Adopting a tree counts as a tradition for cost scaling — several adoptions you never finish still raise the price of the tree you actually want to complete.
• Starving unity income. Traditions are bought with Unity, and early unity competes with everything else that resource does. If your tradition plan stalls, the fix is usually more unity production, not different tree picks.

Advanced tips

• Sequence for perk timing, not tree power. If a build hinges on a specific ascension perk, rush any first tree to its finisher to open the slot — a key perk at year 20 is worth far more than a slightly better tree order at year 40.
• Evaluate your authority’s variant. Gestalt players should judge Synchronicity and Logistics directly instead of following Harmony/Commerce advice written for individualist empires.
• Exploit adoption-vs-finisher asymmetry. Some trees have strong adoption bonuses but modest finishers (adopt early, complete whenever); others are the reverse (only open them when you can afford to finish in one push).
• Match the tree to the next 20 years, not the whole game. Expansion pays off while you’re still grabbing systems; Supremacy pays off when a war is actually coming. Buying a tree “for later” means paying early-game prices for late-game value.

FAQ

Can I refund or change traditions after picking them? No. Tradition and tree choices are permanent for the run in the unmodded game, which is exactly why the 7-slot limit deserves real planning before you spend your first point.

How many ascension perks can I unlock? Eight slots total — seven from completed trees plus one from the Ascension Theory technology.

Do machine or hive-mind empires get different trees? Yes. Machine Intelligences swap Adaptability for Versatility, Gestalt Consciousnesses swap Harmony for Synchronicity and Commerce for Logistics, and the ascension trees carry their own empire-type and DLC restrictions on top.

Should I always open with Expansion? It’s the most common first pick because early territory compounds, but it’s not mandatory — tall builds, machine empires, or military rushes can all justify other openers. Pick the tree that matches what your empire is actually doing in the first two decades, not the one a tier list liked.