Astrophysics is the only research in OGame that simultaneously unlocks two completely different game systems: additional colony slots and additional expedition slots. Every odd level (1, 3, 5, 7…) grants one more colony, and every two levels (2, 4, 6, 8…) grants one more expedition fleet. Understanding that double rhythm — and how the cost curve brutalises you in the high levels — is the foundation of a well-planned empire on any server speed.
The Double Unlock: Colonies and Expeditions
Most research lines do one thing. Astrophysics does two, which makes it unique in the tech tree and uniquely punishing when players ignore it for too long.
Colony slots unlock at every odd level. You start the game with one home planet. Astrophysics 1 gives you slot two. Level 3 gives slot three. Level 5, slot four — and so on up to the server cap (typically eight colonies plus the homeworld, for nine planets total, reached at Astrophysics 15 on standard settings). On OGames the colony cap follows vanilla OGame rules, so hitting level 15 is the long-term endpoint for serious empire builders.
Expedition slots unlock every two levels. You begin with one expedition slot regardless of Astrophysics. Level 2 opens slot two. Level 4, slot three. Level 6, slot four — the pattern continues with the maximum slot count governed by your Computer Technology level as a secondary cap. Each active expedition fleet ties up ships for hours, so the compounding value of extra expo slots over a long session is enormous.
This dual nature means every Astrophysics level you push has a good chance of unlocking something meaningful. But it also means the research never truly becomes "finished" the way, say, Armour Technology does once you hit a comfortable defensive ceiling — there is always one more colony or one more expo slot just two levels away.
The Astrophysics Cost Curve
Astrophysics uses the standard OGame exponential research cost formula. The base costs are relatively modest — Crystal-heavy with a decent Deuterium requirement — but the multiplier per level is 1.75, one of the steepest in the game. For context, most combat techs use a 2.0 multiplier; Astrophysics at 1.75 feels cheap in the early levels and crushes you in the mid-to-late game.
A rough feel for the progression:
- Levels 1–3: Affordable at almost any stage of the early game. A new player on a speed universe should reach Astro 3 within the first day or two of serious play.
- Levels 4–6: Each step costs several times the previous. Research Lab level and possibly the Intergalactic Research Network start to matter here.
- Levels 7–9: This band separates casual colonies from genuine empire expansion. Expect costs in the tens of millions of resources per level depending on server economy speed.
- Levels 10–12: Genuinely expensive. Players often pause here for weeks on standard servers. On OGames speed universes the accelerated production smooths this out considerably.
- Levels 13–15: The final three levels, each costing roughly 1.75× the last. Level 15 is a milestone pushed by late-game dedicated players.
The Crystal demand is the real choke point. Astrophysics scales harder on Crystal than on Metal, and Crystal mines are slower to scale than Metal mines for most players. Budget Crystal carefully and consider holding excess Crystal rather than converting it whenever you know an Astro level is coming up.
Research speed multiplies the base research time but does not change resource cost, so on OGames' faster universes the pain is primarily economic, not temporal. Nebula's 198× research speed, for instance, means level 10 Astrophysics might be queued and completed in minutes — but you still need the resources first.
Odd vs Even Levels: The Strategic Split
Because odd levels unlock colonies and even levels unlock expedition slots, you can — and should — think about which benefit you need more right now before committing to each level.
When to prioritise an odd level (colony)
Push the next odd level when:
- You have more Metal and Crystal production than your existing planets can store or spend efficiently.
- You want to colonise a specific galaxy or system position — for proximity to targets, alliance positioning, or moon creation opportunities.
- Your current planets are already well-developed (Fusion Reactors, large mines, full building queues) and you need fresh build slots.
- You are planning a moon for phalanx coverage and need a planet in the right spot.
When to prioritise an even level (expedition slot)
Push the next even level when:
- Your existing expo fleet is consistently finding good hauls and you have the ships to fill a second or third expedition simultaneously.
- You play long daily sessions and can actively launch and recall expeditions — idle slots are wasted slots.
- You are in a resource-scarce phase and expedition loot provides meaningful income outside your mines.
- Your Computer Technology is high enough to accommodate the additional fleet slot without cannibalising your combat or transport fleets.
The skip trap
Some players try to "skip" an even level by rushing straight to the next odd for the colony, then doubling back for the skipped even. This almost never saves time because costs are strictly cumulative — you cannot bypass a level. What you can do is plan ahead: if you know you need the colony more than the expo slot right now, get both levels in sequence (even first since it is cheaper than the odd that follows), then immediately start the odd. You pay the same total cost either way; the only real choice is which benefit you use first during the research window.
Colony Count Planning
Getting a colony slot is only half the job. Knowing where to plant the colony and what role it will play is the other half.
Slot position vs. field count
Planet slot in the solar system affects maximum fields differently depending on server settings. On OGames, the field bonuses are universe-specific:
- Andromeda adds +500 fields per planet, dramatically reducing the pressure to hunt high-field slots.
- Nebula adds +200 fields, which is still generous by standard OGame norms.
- Proxima adds +500 fields, on par with Andromeda.
On vanilla servers players compete ferociously for slot 6 or 7 positions (the sweet spot for fields and temperature balance). On OGames the field bonus softens that competition, so you have more freedom to choose system position based on strategic location rather than pure field count.
Temperature and Deuterium
Temperature directly affects Deuterium Synthesiser output. Inner-system planets (slots 1–4) run hot and produce less Deuterium; outer planets (slots 8–15) run cold and produce more. Many experienced players deliberately colonise an outer slot — even if it has fewer base fields — specifically to run a high-level Deuterium Synthesiser there. With OGames' massive field bonuses this matters less than on standard servers, but it is still worth considering for your primary Deut planet.
Colony roles
Plan each colony with a job in mind:
- Production colony: Mines and storage, feeds resources into the empire pool.
- Fleet base: Shipyard, nanite factory, positioned near active combat zones.
- Moon anchor: Deliberately placed to generate a debris field for moon creation, then maintained for phalanx or jump gate use.
- Expedition hub: A colony (ideally with a moon for jump gates) near galaxy 1 or wherever expeditions are launched, so expo ships can return quickly.
A nine-planet empire with defined roles for each world is far more productive than nine planets all doing the same thing.
Expedition Slot Growth
Expeditions are one of the most consistently undervalued income streams in OGame, especially on speed servers where ship construction time is compressed. The maximum number of simultaneous expeditions is the lower of: your Astrophysics-derived expo slots, and half your Computer Technology level (rounded down).
In practice this means you need to level both technologies in parallel to extract full value. A player with Astrophysics 10 (five expo slots from Astro alone) but Computer Tech 4 (two expo slots from computer) is only running two expeditions, not five. The calculation is:
Max expo fleets = min( floor(Astrophysics / 2) + 1, floor(Computer Tech / 2) )
Check this formula before every Astrophysics push. If Computer Tech is the binding constraint, it almost always makes sense to level Computer Tech first — it is generally cheaper and also expands your total fleet command capacity for combat and transport simultaneously. See the Computer Technology guide for the full fleet slot breakdown.
Expedition fleet composition
A classic expo fleet on speed servers is a mix of Large Cargo Ships for haul capacity, Pathfinders (on universes that have them) for the expo-specific bonus, and a small escort of combat ships to survive the "expedition battle" events. On OGames you can use the Battle Simulator on the main site to quickly test different fleet compositions before committing ships to the void for hours. The Expeditions on Speed Servers guide covers fleet sizing and risk management in more detail.
Doubling up on expo hubs
With multiple colonies available, consider placing two or three with moons near galaxy 1 (or wherever your alliance fleets gather). Jump gates let you move expo ships between moons instantly, which means a single large expo fleet can effectively serve multiple slots without travel dead time. This synergy between Astrophysics (more colonies, more expo slots) and Moon Technology (jump gates) is one of the most powerful compound effects in the mid-to-late game.
Astrophysics Priorities on OGames Universes
The three OGames universes have different economy speeds, and that changes the optimal Astrophysics pacing significantly.
Andromeda (50× economy)
Andromeda is a measured speed — fast enough to progress daily, slow enough that resource planning still matters. Target Astrophysics 3 (two colonies) in the first week. Aim for Astrophysics 6 by the end of week two to have three expo slots running. The 43% ship debris rate means fleet losses are partially recoverable, so lean into expeditions early; the income smooths out combat losses. The 5,000 DM signup bonus plus 1,000 weekly DM gives you enough Dark Matter to run commanders that speed up research without ever paying, which helps push through the expensive Astro mid-levels faster.
Nebula (99× economy)
Nebula's 198× research speed is the key lever. Research levels that take days on Andromeda complete in hours here. The practical implication: push Astrophysics more aggressively than you think is prudent. You can reach Astrophysics 6 or 7 in the first few days of active play. The 10,000 DM signup plus 10,000 weekly DM is generous enough to keep commanders active constantly, and the 55% ship debris rate rewards aggressive expo fleets. Aim to have three to four colonies established within the first week and use the extra production capacity to fund the increasingly expensive upper Astro levels.
Proxima (200× economy)
Proxima is the "all gas, no brakes" universe. The 400× research speed means even high-level Astrophysics completes quickly. Players who play actively in Proxima can reach Astrophysics 10+ within the first week of serious grinding. The 80% ship debris rate is enormously important here — expo fleets that get destroyed return the majority of their cost in debris, making expeditions almost risk-free income. The 20,000 DM signup plus 50,000 weekly DM means every player is running full commanders permanently. In Proxima, Astrophysics should be a top-three research priority from day one; the compounding effect of extra expo slots at 200× economy speed is staggering. If you want to see just how fast a well-managed Proxima empire can scale, compare all three universes here.
Universal priority order
Regardless of universe, the early-game Astrophysics priority order is roughly:
- Reach Astrophysics 1 as soon as the prerequisites allow (Energy Tech 1, Impulse Drive 3).
- Push to Astrophysics 2 for the second expo slot — early expedition income is critical.
- Push to Astrophysics 3 for the second colony — begin empire expansion.
- Alternate between the next even and odd levels based on whether expo income or colony expansion is the bigger need at that moment.
- Never let Astrophysics sit at an even level longer than necessary if you have a colony slot planned — the odd level is always one research away.
The research prerequisites are worth stating plainly: you need Energy Technology level 1 and Impulse Drive level 3 before you can even queue Astrophysics 1. Neither is expensive on a speed server, but new players sometimes overlook Impulse Drive because it sits in the Drives branch rather than the Research branch. The Drives guide covers Impulse Drive in context if you need to plan the unlock path.
FAQ
What are the prerequisites for Astrophysics in OGame?
You need Energy Technology level 1, Impulse Drive level 3, and a Research Lab on your planet. These unlock Astrophysics 1. From there each subsequent level simply requires the previous one plus the resources and research time. On OGames' speed universes the prerequisites take very little time to reach — most players can start Astrophysics within the first few hours of the game.
Does Astrophysics level affect moon creation chance?
No. Moon creation chance depends on the size of the debris field left by a battle, not your Astrophysics level. On OGames, moon chance is capped at 20% in Andromeda, 30% in Nebula, and 40% in Proxima — those are server-side caps set in the universe configuration, independent of your tech levels. What Astrophysics does affect is how many colonies you have available to create debris fields from, which indirectly supports a moon farming strategy.
Is it ever worth skipping straight to a high Astrophysics level early?
Not in the sense of skipping intermediate levels — OGame requires every level to be researched in sequence. But the question of whether to rush Astrophysics at the expense of combat techs is real. In general, on speed servers the answer is yes for the first six to eight levels, because production income from additional colonies and expedition hauls compounds faster than the incremental combat power from weapon or shield upgrades. After Astrophysics 8 or so, the cost curve typically means you should balance Astro investment with other research priorities based on your playstyle.
How does Astrophysics interact with the Research Network (IRN)?
The Intergalactic Research Network (IRN) allows multiple Research Labs across your colonies to cooperate on a single research, dramatically cutting research time for expensive techs. Astrophysics itself does not require IRN to research, but IRN becomes very valuable when pushing Astrophysics levels 8 and above because those levels have enormous research times on standard servers. On OGames the high research speed multiplier (100× in Andromeda, 198× in Nebula, 400× in Proxima) means IRN matters less for time, but it still matters if you want to shave hours off the highest levels.
Should I max out colonies before pushing for more expedition slots, or vice versa?
Neither absolute strategy is optimal. The right approach is situational: if you have idle production capacity (ships, resources sitting in storage overflow) and no new planets to spend them on, push the next odd level for a colony. If you have ships ready to fly expeditions and more active play time than expo fleets to fill it, push the next even level for the slot. In practice most players are better served by treating Astrophysics as a continuous background research — always queued, always progressing — rather than "maxing" one aspect before touching the other. The two benefits are complementary: more colonies produce more ships and Deuterium to fuel more expeditions, and more expedition income funds the resources needed for more colonies.
Ready to put Astrophysics theory into practice? Register on OGames and pick your speed — whether you prefer the strategic pace of Andromeda, the mid-gear grind of Nebula, or the full-throttle chaos of Proxima, all three universes are live and free to join today.