The Search for Planet X
Survey sectors, target specific locations, research new logic rules and publish theories while a shared time track determines who acts next. Planet X itself appears empty, so finding it requires deduction rather than a lucky direct scan.
The Search for Planet X is a deduction game by Matthew O’Malley and Ben Rosset. Players are astronomers trying to identify a hidden arrangement of objects in the outer solar system, publish correct theories and eventually locate Planet X itself.
BoardGameGeek currently shows roughly 16,100 ratings, an average around 7.89, an overall rank around #118 and a complexity rating around 2.43 / 5. Community voting favors 2–3 players, while solo is fully supported.
Why it stands out
Planet X cannot simply be scanned and revealed like an ordinary object. The app reports its sector as appearing empty, and a successful Locate Planet X action requires you to name not only its sector but also the objects on both adjacent sides. The final discovery therefore rewards actual logical deduction rather than repeated guessing.
Why this is a strong evergreen search gap
The game combines a large established audience with a rules structure that naturally creates search questions around action timing, theories, Planet X scoring, Expert Mode and app use.
The main long-tail opportunities include how to play The Search for Planet X, Survey rules, Target action, Research action, Locate Planet X, theory scoring, peer review, time track, visible sky, Standard vs Expert Mode, solo rules, app requirement, GM Kit and strategy.
Game at a Glance
Choose One Action
Survey, Target, Research or attempt to Locate Planet X.
Pay Time, Not Money
Every action moves your pawn a different distance. The player furthest behind acts next.
Publish Theories
Commit deductions before rivals, then wait for peer review to reveal whether you were correct.
Locate Planet X
Name Planet X’s sector plus both adjacent objects to trigger the endgame.
How The Search for Planet X works
At the start of a game, the companion app creates a hidden arrangement of objects that obeys a fixed set of logical rules.
Players receive different starting information depending on their selected experience level, then take actions to reveal more information privately.
The board’s outer ring is also a time track. Rather than using clockwise turn order, the player whose pawn is furthest behind acts next.
The goal is to earn the most renown through correct theories and by locating Planet X.
The three parts of a turn
- Take one action — Survey, Target, Research or Locate Planet X.
- Advance your pawn by that action’s time cost.
- Rotate the Earth board until its arrow points toward the new player furthest back on the time track.
Rotating Earth can pass Theory or Conference icons, triggering those shared phases before normal play continues.
The four actions and their time costs
| Action | Time cost | What you learn/do |
|---|---|---|
| Survey 1–3 sectors | 4 | Learn how many of one chosen object type are present in the selected visible range. |
| Survey 4–6 sectors | 3 | Same idea, but across a larger visible range. |
| Survey 7–9 sectors | 2 | Expert Mode only. |
| Target a Sector | 4 | Learn the exact object in one sector, or that it appears empty. Limited to two uses per player. |
| Research a Topic | 1 | Gain one additional logic rule. Cannot Research twice in a row. |
| Locate Planet X | 5 | Name Planet X’s sector and both adjacent objects. |
How Survey works
Survey asks the app how many objects of one chosen type appear within a selected consecutive range of visible sectors.
You do not learn exactly where those objects are — only the total.
Smaller survey ranges cost more time because the answer is more precise. Wider surveys are cheaper but produce less concentrated information.
This creates a core deduction trade-off: spend four time units for a tight 1–3 sector count, or spend less time to learn a broader pattern.
How Target a Sector works
Target is the most direct information action.
Select a visible sector and the app tells you which object is there, or tells you that it appears empty.
Each player has only two Target uses, represented by target tokens.
Because Planet X itself also appears empty, a Target result of “appears empty” does not prove that the sector is truly empty.
How Research works
Research costs only 1 time, making it the fastest standard action.
The app gives you one additional logic rule about the hidden arrangement.
Research cannot be chosen on consecutive turns by the same player.
Research is especially useful when one global relationship can eliminate many possible sectors at once.
Why Planet X appears empty
Planet X has a special property: ordinary scans do not identify it.
Survey and Target information treats the Planet X sector as appearing empty.
That means players must distinguish between:
- Truly Empty — no object exists in the sector.
- Appears Empty — either truly empty or Planet X.
This distinction is the central logic twist of the game.
How to Locate Planet X
The Locate Planet X action costs 5 time.
You must identify:
- The sector containing Planet X.
- The object immediately clockwise from it.
- The object immediately counterclockwise from it.
The app verifies the complete claim.
If correct, the game enters its final scoring sequence. Merely knowing the likely Planet X sector is therefore not sufficient.
What is the Visible Sky?
Not every sector is available for every observation at all times.
The Earth board defines the current Visible Sky, representing the portion of the outer solar system that can currently be observed.
As players spend time and the Earth board rotates, different sectors become accessible.
A theoretically perfect observation can therefore be unavailable simply because the relevant sector is not currently visible.
Why the time track matters
Turn order is dynamic.
The player furthest back on the time track acts next, which means choosing a cheap Research action may let you act again before a rival who just spent four or five time on a more powerful observation.
This creates a second optimization layer beyond pure logic: information has a time price.
Editorial strategy principle: compare actions by information gained per time spent, not just by how certain the answer will be.
How Theory phases work
When the rotating Earth board passes a Theory icon, players may submit predictions about which object occupies a sector.
Theories are placed face down on the sector’s peer-review track.
During later Theory phases, those tokens move toward the center.
When a theory reaches the peer-review position, it is checked through the app. Correct theories remain for final scoring; incorrect theories are removed and cost the player 1 time.
Why submitting a theory early can score more
A correct theory scores its normal object value at the end of the game.
In addition, the player who was first — or tied for first — to submit the correct theory in that sector gains a 1-point leader bonus.
Publishing early therefore has a benefit, but it also reveals information to rivals once peer review confirms the object.
Theories are consequently both scoring opportunities and controlled information leaks.
What happens during a Conference?
Conference icons on the board trigger shared information.
The app reveals a new logic statement about Planet X to all players.
Standard Mode includes fewer Conference events than Expert Mode.
Because every player receives the same clue, a Conference often causes several people to reach similar deductions at once — making theory timing especially important immediately afterward.
The Search for Planet X scoring
| Scoring source | Points |
|---|---|
| First/tied-first correct theory in a sector | +1 leader bonus |
| Correct Asteroid theory | 2 |
| Correct Comet theory | 3 |
| Correct Gas Cloud theory | 4 |
| Correct Dwarf Planet theory | 4 Standard / 2 Expert |
| First player to correctly locate Planet X | 10 |
| Later correct Planet X location | 2 × sectors behind discoverer, max 10 |
The highest total wins. Ties are broken first by Planet X points, then by leader-bonus points; if still tied, players share the victory.
What happens after someone finds Planet X?
A correct Locate Planet X action triggers the endgame.
The discoverer advances five spaces but the Earth board is not rotated normally.
Other players may receive one final scoring opportunity depending on how far behind they are:
- 1–3 sectors behind: submit up to one theory or attempt to locate Planet X.
- 4–5 sectors behind: submit up to two theories or attempt to locate Planet X.
Then hidden theories and objects are resolved and final scores are calculated.
Standard Mode
Standard Mode uses 12 sectors.
The standard note sheet includes:
- 2 Comets
- 4 Asteroids
- 1 Dwarf Planet
- 2 Gas Clouds
- 1 Planet X
- 2 truly empty sectors
It is the recommended learning mode because there are fewer sectors and fewer dwarf planets to track.
Expert Mode
Expert Mode expands the board to 18 sectors.
It uses four Dwarf Planets instead of one and introduces additional complexity through the larger information space.
Players also use Expert panels and have access to longer-range 7–9 sector Surveys.
Correct Dwarf Planet theories are worth 2 points each in Expert Mode rather than 4, reflecting the larger number available.
Beginner, Experienced and Genius starting information
Players do not all need to receive the same amount of starting help.
The app can provide different levels of initial information:
- Beginner
- Experienced
- Genius
This allows mixed-skill groups to play the same hidden setup while stronger deduction players receive less starting information.
How solo play works
The official solo game pits you against an app-controlled bot.
You set up your own player normally, then add a bot pawn and theory tokens.
When you are furthest back on the time track, you take a normal turn. When the bot becomes active, the app determines its action and theory behavior.
The bot can submit theories and score for them, so solo remains a competitive deduction race rather than a simple “find Planet X before a timer” puzzle.
Do you need the companion app?
The free companion app is the normal way to generate the hidden solar system, deliver private Survey/Target/Research information, verify theories and manage solo.
Multiple players can use separate devices or share a device.
However, Renegade now provides an official GM Kit that allows app-free play with one person managing the hidden information.
So the current answer is: the app is the standard method, but it is no longer the only official method.
How much does The Search for Planet X cost?
Renegade’s current retailer listing shows an MSRP of $45.
The listed box includes the Solar System board, rotating Earth board, Sun disc, theory tokens, screens, target tokens, player miniatures, double-sided note sheets, Expert Mode cards and rulebook.
Actual retail pricing varies by store and region.
The Search for Planet X vs SETI
| Feature | The Search for Planet X | SETI |
|---|---|---|
| Main genre | Logical deduction | Euro strategy / engine building |
| Information | Hidden and progressively deduced | Mostly public strategic systems |
| App | Standard information engine; GM Kit alternative | Not required for core play |
| Interaction | Race to publish theories and solve Planet X | Competition over actions, scoring and alien discoveries |
| Best fit | Players who enjoy Sudoku-style logical elimination | Players who want a heavier space-science strategy game |
Eight strategy principles for new astronomers
- Write every deduction down. Memory is much less reliable than disciplined elimination.
- Value information per time unit. A 1-time Research can outperform a 4-time Target if the rule eliminates many sectors.
- Use Target on ambiguous bottlenecks. Save the limited direct observations for sectors that separate several plausible solutions.
- Remember that Planet X appears empty. Never mark every “appears empty” result as truly empty.
- Publish when confidence is high enough, not perfect. Waiting for certainty can surrender leader bonuses.
- Watch rivals’ time positions. A player far behind may receive multiple actions before your next turn.
- Recalculate after peer review and Conferences. Shared information can collapse the possibility space dramatically.
- Do not rush Locate Planet X with only the central sector solved. You also need both adjacent objects correct.
Seven things to know before buying
- This is a true deduction game. Most enjoyment comes from note-taking and logical elimination.
- The app is free and central to normal play.
- App-free play is now officially supported through Renegade’s GM Kit.
- Players can use different starting-information difficulties in the same game.
- Standard and Expert modes use meaningfully different board sizes.
- Solo is a competitive game against an app-controlled bot.
- Locating Planet X does not automatically guarantee victory. Correct theories can create a higher final score.
The Search for Planet X FAQ
How many players?
1–4 players.
How long does it take?
Renegade lists 60–75 minutes.
Who designed it?
Matthew O’Malley and Ben Rosset.
What are the four actions?
Survey, Target a Sector, Research a Topic and Locate Planet X.
Who takes the next turn?
The player whose pawn is furthest behind on the time track.
How many times can you Target?
Twice per player.
Does Planet X show up when targeted?
No. Its sector appears empty, just like a truly empty sector.
How do you successfully locate Planet X?
Name its sector and both adjacent objects correctly.
How many sectors are in Standard Mode?
12.
How many sectors are in Expert Mode?
18.
Can it be played solo?
Yes. The official app controls a bot opponent.
Is the app mandatory?
It is the standard method, but Renegade now provides an official GM Kit for app-free play.
How much is it?
Renegade currently lists a $45 MSRP.
Sources and scope
- Renegade Game Studios: official product page, 1–4 players, 60–75 minutes, app, GM Kit and printable sheets
- Renegade retailer page: current $45 MSRP and box contents
- RulesPal rulebook reference: actions, time costs, Standard/Expert setup and app structure
- Rule reference: four actions, theory scoring, final opportunities and tiebreakers
- BoardGameGeek file archive: official rulebook
- BoardGameGeek: current rank, ratings, player count, complexity and play time
Checked October 10, 2026. The original rulebook was written around app-assisted play, while Renegade now also provides an official GM Kit for app-free sessions. Strategy and buyer guidance are original editorial analysis; no firsthand review or playtest is claimed. Editorial policy and corrections.