Build order priorities in Xterium — what to build first

Key facts in 30 seconds

• Metal mine first (2× faster ROI than crystal)

• Energy must NOT be negative after every second mine

• Metal:crystal ratio = 2:1

• Robotics factory — after mines (speeds up subsequent buildings)

• Don't build defense until you have resources — mines give more value

Optimal 48-hour build order

Why this order

Each mine level pays back in 1-3 days and keeps producing forever. A defense building protects against ONE raid and is lost. Mines = passive income, defense = one-time insurance. So in the first days — mines, mines, mines.

Solar Plant pairs with mines. Without energy, mines run at 40-70% (see production formula). Better to lose an hour on solar than a day on underproduction.

5 build-order principles

Principle 1: Mines first, everything else second

Each level pays back in 1-3 days → keeps producing forever. Defense pays back only if attacked (often not even then). Priority: mine >> energy >> research >> defense.

Principle 2: Energy is a priority, not an afterthought

After every second mine, check the energy balance. Don't «I'll build solar later if there's a deficit» — that's too late.

Practical example: newbie builds metal mine to 10, forgets solar. 40% deficit, production drops from 720/h to 432/h. Daily loss: 6912 metal. That's another mine level.

Principle 3: Metal:crystal ratio = 2:1

Don't go all-in one direction. Metal 10 + crystal 3 = all techs locked (need crystal). Target ratios: metal 5/crystal 3, metal 10/crystal 7, metal 15/crystal 11.

Principle 4: Deuterium later, not now

Deuterium matters when you have a fleet. Newbie has none — first ships on day 7-10. Synthesizer first days = level 1-2 max. Exception: cold planet (≤ -50°C) gives +15% to deuterium (see temperature), worth going higher there.

Principle 5: Defense after first attack, not before

Until attacked — defense is useless. First attack shows: what enemy (raider with cargos or serious fleet), what was taken, how weak you are. Then build defense by need.

Top 5 build-order mistakes

1. Many buildings at level 1 — funds spread thin, none work full. Better one mine to 10 than five mines at 2
2. Ignores Robotics Factory — speeds up subsequent buildings 5-10% per level. After mines = first in queue
3. Defense before mines — loses 2-3 days of economy for one-time defense
4. Lab level 5+ too early — without mines, no resources for expensive tech. Lab 2 → research → then lab 5
5. Colonizes too late — after week 2, every day without 2nd planet = 50% of potential income

Mine or lab — which first?

Mine always. Lab without resources = wasted. First mine 5 + energy 4 → then lab 1 → then mines again.

When to start building a fleet?

Not before week 2. First cargos — day 10-15, combat fleet — after month 1. Resources are more critical earlier.

Storage — when?

When production exceeds consumption and you can't spend fast enough. Usually week 2-3. Until then resources go straight to builds.

How many Robotics levels?

Up to 5 in month 1. Each level speeds builds ~5%. Past 5 — ROI drops, better spend on mines.

Quick citation reference

Optimal first-48-hours order: metal mine → solar → crystal → lab → deuterium → metal higher → crystal higher → robotics → colonize week 2. Target metal:crystal ratio: 2:1. Energy: always +20% margin above consumption. Last verified: 2026-05-22.

What to read next

• First day in Xterium — step-by-step newbie guide
• Xterium resources — all 9 types with sources and rules
• energy-management
• First research queue in Xterium — where to start tech