The Search for Planet X
Use a companion app to investigate the night sky, combine private results with published theories and deduce Planet X’s location; total points decide the winner.
The Search for Planet X supports 1–4 players; community best: 2–3 players; playing time: 60–75 minutes. A WANGO browser trial has not been confirmed.
Background & introduction
The sky is divided into sectors, with asteroids, comets, gas clouds, dwarf planets and truly empty sectors following different placement rules. The app holds the solution, while players combine private investigations with public information to eliminate impossible locations.
Turns follow the player farthest back on the time track rather than a fixed clockwise order. Different actions and survey ranges cost different amounts of time. An efficient research action can bring your next turn sooner, but does not simply reveal the whole solution.
Publishing theories earns points for correct objects and early contributions, while locating Planet X triggers the endgame. Players behind the discoverer can still receive a final scoring opportunity, so deductions, publication and time-track position must be weighed together.
Core rules & scoring
Sky and logic: Standard Mode has 12 sectors and Expert Mode 18; half are visible at a time. Each sector holds one object or is truly empty. Asteroids neighbor another asteroid, comets occupy designated sectors, gas clouds neighbor truly empty sectors and dwarf planets never neighbor Planet X. Expert Mode has four dwarf planets in a band of exactly six sectors, with one at each end.
Turn order: The farthest-back pawn acts and advances by the action’s time cost. When arriving in an occupied sector, place it ahead of the pawns already there, who act first. Rotate Earth one sector at a time toward the new farthest-back pawn, pausing at conference and theory icons.
Survey and target: Survey one object type over consecutive visible sectors: 1–3 sectors cost four time, 4–6 cost three, and Expert surveys of 7–9 cost two. A comet survey must start and end in possible comet sectors. Targeting one visible sector costs four time and is limited to twice per game. Both treat Planet X as empty; results are private, but announce the chosen object and range or target sector.
Research and conferences: Research costs one time and provides a private logic clue for a topic, but you cannot research on two consecutive turns of your own. The first time Earth reaches each conference icon, everyone receives a public clue about Planet X. Later passes do not repeat that conference.
Locate Planet X: Pay five time and identify its sector and the contents of both adjacent sectors; all three must be correct. Announce success or failure without revealing your chosen sector. On success, advance five sectors and go straight to the endgame without rotating Earth; discovery does not guarantee victory.
Theories and peer review: Simultaneously select up to one theory in Standard or two in Expert Mode, for any unconfirmed sectors. Place them on the outer spaces, then advance all new and existing face-down theories inward one space. Review those reaching the inner space. Remove incorrect theories and penalize one time each. A correct theory confirms the sector and exposes its outer theories too; correct theories remain in place.
Final opportunities: After the discoverer advances five sectors, anyone at least one sector behind may locate Planet X or submit theories: at most one from 1–3 sectors back, or two from 4–5 back. Resolve these opportunities from back to front without moving pawns. Reveal all objects and check the remaining theories afterward.
Scoring: Correct asteroid/comet/gas-cloud theories earn 2/3/4 points; dwarf planets earn four in Standard or two each in Expert. The earliest correct theory in each sector, including tied earliest submissions, earns a one-point bonus. First discovery earns ten; later successful final attempts earn two per sector behind, from two to ten. Break total-score ties by Planet X points, then leader bonuses, then share victory.
Rules & gameplay questions
Does an empty target result rule out Planet X?
No. The app reports Planet X as empty. Combine placement rules and other information, including neighboring contents, to distinguish it from a truly empty sector.
Does the first discoverer always win?
No. The first discovery earns ten points and triggers the endgame. Eligible players behind can still score, and correct theories and leader bonuses also count toward the final total.
Must I announce my survey result after announcing its range?
No. Announce the chosen action, object and range as required, but keep the app’s investigation result private. Conference clues and confirmed theories are public information.
If the app lets me inspect an invisible sector, is that legal?
No. The official FAQ explains that the app deliberately does not track the visible sky, allowing shared devices, replacements and result checks. Players must enforce the visible-sky restriction for surveys and targets, and apply time penalties on the physical track.
Are theories restricted to the visible sky?
No. You may submit in any sector not already confirmed by peer review, including invisible sectors. You cannot duplicate an identical theory in one sector, or submit two different theories there during the same phase.
Rules & introduction sources
- Edition
- Original The Search for Planet X, using the official Foxtrot English P1B rulebook (2020, 20 pages), especially actions and endgame on pages 8–16 and scoring on page 17. Covers 2–4-player Standard and Expert games using the companion app; excludes separate solo rules and the Game Master Kit.
- Rule references
- Introduction source
- BoardGameGeek
WANGO editorial
| Parameter | Recorded value |
|---|---|
| BGG overall rank (snapshot) | #116 |
| Complexity Weight | 2.43 / 5 |
| Best player count (community) | 2–3 |
| Player range | 1–4 |
| Playing time (minutes) | 60–75 |
| Core mechanisms | Action Points · Deduction · End Game Bonuses · Paper-and-Pencil · Rondel · Solo / Solitaire Game · Turn Order: Time Track |
| Chinese publication | Unconfirmed |
| WANGO browser play | No confirmed WANGO trial |
| Year published | 2020 |
| Suggested age | 13+ |
BGG statistics are stored snapshots, not live rankings. Source checked：2026-09-27
Player questions
What is the best player count for The Search for Planet X, and can I play online?
The Search for Planet X supports 1–4 players; community best: 2–3 players; playing time: 60–75 minutes. A WANGO browser trial has not been confirmed. Recorded mechanism tags: Solo / Solitaire Game.
How complex is The Search for Planet X, and which mechanisms does it use?
Weight: 2.43 / 5. Mechanisms: Action Points · Deduction · End Game Bonuses · Paper-and-Pencil · Rondel · Solo / Solitaire Game · Turn Order: Time Track. Chinese publication: Unconfirmed.
Where can I learn The Search for Planet X?
No rule guide, strategy article or WANGO trial has been confirmed for this record.