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Chaos Cosmos
Build your own solar system — Rule the chaos
A card game for 2–5 players · 20–60 minutes · ages 8+
Made for every friend of the cosmos
← Back to the gameObject of the game
Build your own solar system before chaos takes over.
Everyone builds their own solar system. At the start of the game you receive a Sun card: place it in front of you face up. You play planets to the right of your Sun, face up — so everyone can see what you have. The Sun is not one of the cards you collect; whether you have it or not does not affect victory. A Sun cannot be destroyed or taken from another player.
You win when all eight different planets are in place (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune), and you do not have the Glitch (see later) either in your hand or in your solar system.
A Plotuh (see later) may stand in as a joker for one missing planet — only one such card may be in play in your solar system at a time. Duplicates do not count toward the eight.
The draw pile can run out. If it is empty when you must draw, the player whose turn it is finishes their turn (two actions and a discard). Then clockwise, everyone else may take 1 more action (no draw, no discard). The player who emptied the pile does not get an extra action. After that the game ends: the winner is whoever has the most different planets in their solar system (Plotuh may substitute one missing planet) and does not have the Glitch in hand or in play — the Glitch always blocks victory. On a tie, more real planets, then the earlier seat. Everyone’s hand is then revealed, and the program explains who won and why. Completing 8 planets during the closing round still wins immediately.
Setup
Setting the table
Deck size depends on the number of players. Exact counts are in the Deck composition section: assemble the deck accordingly, then shuffle thoroughly.
Each player receives a Sun and places it face up in front of them. Do NOT put any leftover Sun cards into the draw pile! Then each player draws five cards into their hand — only they may see these.
The remaining cards go face down in the middle of the table: this is the draw pile. Leave space beside it for the discard pile (which starts empty). Draw for a starting player — or let whoever last saw a clear, starry sky go first.
Turn structure
Always in this order
1. Draw. Draw two cards from the top of the draw pile. If your hand was completely empty at the start of your turn, first draw five cards, then immediately draw the mandatory two. If the draw pile runs out, shuffle the discard pile: that becomes the new draw pile.
1. Draw. Draw two cards from the top of the draw pile. If your hand was completely empty at the start of your turn, first draw five cards, then immediately draw the mandatory two. The draw pile can run out: if it is empty when you must draw, the discard pile is not shuffled back in. The player who would draw finishes their turn with the cards they already drew (two actions + discard), then clockwise everyone else gets 1 more action, with no draw and no discard. The player who emptied the pile does not get an extra action — then the game is scored, and everyone’s hand is revealed.
2. Two different action categories. You may take two actions in a row, in any order, but they cannot be from the same category. You may pass at any time — any remaining actions are skipped. The categories:
2. Two actions, fixed order. First action: anything that is not placing a planet or Plo-Tuh (including a swap), or a pass. Second action: exactly one planet or Plo-Tuh placement (own swap and claiming an opponent’s Plotuh count), or a pass. The two actions may share a category — e.g. place the Glitch, then a planet. In the closing round you get one action of either type. Categories (for reference):
- Placement: play a missing planet or Plotuh into your solar system; claim a Plotuh swap from another player’s system; place the Glitch from hand into another player’s system (blockable).
- Theft / draw: Gravitational Pull or Magnetic Storm (from an opponent’s hand, solar system, discard top, or draw pile); Wormhole search.
- Attack / destruction: Supernova or Meteor Shower; move the Glitch by sacrificing your own planet; discard Black Hole + Glitch.
If you acquire a planet first (Wormhole, Gravitational Pull, Plotuh swap), you may place it as your second action — but only if your first action was not placement. If you place a planet first, one acquired as the second action cannot be placed this turn.
Planet/Plo-Tuh placement is always the second action. If Wormhole or Gravitational Pull was first, you may place the found/stolen planet as the second. Passing the first action keeps the planet slot — that is how you can win with a single placement.
3. Discard. You must always end your turn by discarding one card from your hand, face down onto the discard pile, so the other players cannot see what you discarded. At the end of your turn you may have at most seven cards in hand; discard any extras. The Glitch cannot be discarded on its own. It is the only card that can be discarded only together with the Black Hole! In that case the player discards 2 cards in one turn. If your hand is empty, the mandatory discard is skipped.
Planets and Plotuh
The eight celestial bodies and the joker
The planets you collect: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Play them to the right of your Sun in any order. You may only play a type you are still missing. The Sun is not a collectible card, so whether you have it or not does not affect the outcome of the game.
Plotuh may take the place of any missing planet. When you play it, you must clearly name which planet it is substituting for — you cannot change this later while the card remains on the table. Each solar system may have only one Plotuh in play at a time.
If you have in hand the planet that Plotuh is currently substituting for, you may swap them on your turn: the real planet goes onto the table, and Plotuh returns to your hand. This swap counts as an action — you cannot swap again that turn, but you may still take your other, different action.
If an opponent’s Plotuh is substituting a planet that is in your hand, you may make the same swap as your action: you place that planet into their solar system in Plotuh’s place, and Plotuh goes to your hand. Placing that Plotuh is a separate action — if the swap was first, you may place it as the second.
Action cards
They do not go into your solar system
You do not place action cards next to your Sun. When you play one, put it in the middle of the table, beside the discard pile, face up so everyone can see it. After the effect resolves — at the end of your turn — the card goes face down on top of the discard pile.
The discard pile is always face down. There are three main groups: attack cards, defense cards, and the specials — Glitch, Black Hole and Wormhole.
Playing a Wormhole is a search action, distinct from an attack: if you use it, you may still take a different kind of action that turn — for example placing a planet, including the one you just found.
Attack
Four ways to disrupt your opponents
Gravitational Pull: choose an opponent and a real planet in their solar system. That planet goes into your hand — you are not required to place it. Placing it is a separate action: if the Pull was first, you may place it as the second; if you already placed a planet this turn, only on your next turn. Plotuh cannot be stolen with Gravitational Pull, even if it is substituting a named planet. If they have no real planet to steal, you must choose another target, or the card goes to the discard pile with no effect.
Magnetic Storm: when you play it, choose one: A) choose an opponent; they shuffle the cards in their hand, and you blindly draw one card from them at random into your own hand (this can be blocked); or B) take the top card of the discard pile into your hand (cannot be blocked; cannot be played if the discard pile is empty); or C) draw one extra card from the draw pile into your hand (cannot be blocked). If the draw pile is empty, the discard pile is shuffled back in, as with a normal draw. In modes B and C the Storm goes onto the discard pile after you take / draw the card.
Magnetic Storm: when you play it, choose one: A) choose an opponent; they shuffle the cards in their hand, and you blindly draw one card from them at random into your own hand (this can be blocked); or B) take the top card of the discard pile into your hand (cannot be blocked; cannot be played if the discard pile is empty); or C) draw one extra card from the draw pile into your hand (cannot be blocked). If the draw pile is empty, mode C cannot be played — the discard is not shuffled back in. In modes B and C the Storm goes onto the discard pile after you take / draw the card.
Supernova: choose a planet from any player's solar system — it is destroyed and immediately goes to the discard pile.
Supernova (playtest): destroy a named planet (or Plo-Tuh) in an opponent’s solar system. The card stays face-up as a shield until the end of their next turn — they cannot be hit by Supernova while it lasts (other attacks still work). When the shield drops it goes under their discard so their discard lands on top. The victim blindly discards one card from the attacker’s hand. Mirror fully reflects the effect (shield and tax); the original attacker may only Breakthrough, not Atmosphere/Mirror.
Meteor Shower: name a planet type. Everyone — including you — who has that planet in their system on the table discards it.
Meteor Shower (playtest): choose an opponent. Their whole hand (shuffled) goes under the discard pile, then they take the top 5 cards of the discard (or fewer if fewer remain). An empty or short discard is allowed. No per-turn cooldown. The Glitch may leave their hand this way because they did not discard it. It can be defended; Mirror fully reflects onto the caster (who may only Breakthrough).
Defense
Shield, mirror and breakthrough
If you are attacked, you may play a defense card from your hand in response.
Atmosphere: the attack fizzles with no effect — both cards go onto the discard pile.
Cosmic Mirror: it does not merely block; it reverses the effect: the original attack takes effect against the attacker.
Breakthrough: if the attacker has another attack card of the same name as the one they just played, they may play it immediately to override the defender's block. The defender may respond again with any card suitable for defense, and the chain continues until one side runs out of the appropriate card. The last card played decides the outcome. Importantly, the attacker cannot counter-attack with a Cosmic Mirror! (See the “Special cases” chapter.)
Breakthrough (playtest): exactly three steps. 1. Attack. 2. The target may play Atmosphere or Mirror, or nothing. 3. If there was a defense, the attacker may play another attack card of the same name — it breaks through, the effect applies, the chain ends. The defender cannot answer step 3. No fourth card, not even in the closing round.
Glitch
A flaw in reality — while you have it, you cannot win
While the Glitch is in your hand or in your solar system, you cannot win — even if you already have all eight planets.
In hand: the Glitch cannot be discarded on its own. The only exception: if you also have the Black Hole in hand, you may discard both cards at once. There is always only one Black Hole in the deck.
In your solar system: on your turn (this uses one of your two actions) you may destroy one of your own planets and move the Glitch into another player's solar system. This relocation cannot be defended against. The Glitch's first placement, however, can be blocked — when it first enters someone's solar system from a player's hand.
Wormhole
Searching the depths of the draw pile
Playing a Wormhole counts as an action. Name a planet type you are still missing. Then, from the top of the draw pile, turn cards face up one by one, openly in front of everyone, until you find the planet you are looking for, or until the draw pile is empty.
Playing a Wormhole is an action (search), not an attack. The search is secret: only you look at the cards. You do not name a planet in advance.
If you find it, take it into your hand. The search itself does not place it into your solar system — placing it is a separate action. If the Wormhole was your first action, you may place the planet as the second; if you already placed a planet this turn, only on your next turn. Then shuffle the revealed cards (except the planet you found), the remainder of the draw pile and the entire discard pile: that becomes the new draw pile.
Take the top 6 cards of the draw pile (or fewer if fewer remain). You may put one planet, Plo-Tuh or Glitch into your hand. You are not required to. Black Hole and action cards cannot be taken. Shuffle the rest and put them on the bottom of the draw pile — the rest of the draw pile and the discard stay put. If Wormhole was your first action, you may place the found planet/Plo-Tuh as the second. Placing the Glitch from hand can only be the first action.
Glitch, Black Hole and Plotuh can never be searched for with a Wormhole. A Wormhole can search only for a planet. If the search fails, you do not receive a planet, but the piles must still be shuffled together to form a new draw pile.
The Supernova shield only blocks Supernova. Meteor Shower swaps the hand, not the table. Mirror always fully reflects: the attacker suffers as if they were the original target, and may only Breakthrough (not Atmosphere/Mirror).
Special cases
Where the edges of the rules meet
In a response chain the target decides first, then the attacker — no other player may intervene. On a Meteor Shower, affected players discard clockwise, starting with the player after the one who played the card.
If a Supernova or Meteor Shower destroys the slot occupied by Plotuh, Plotuh goes to the discard pile. Plotuh cannot be stolen with Gravitational Pull — even if the named planet matches.
If a player plays an attack card and the defender blocks it by playing Cosmic Mirror, the attacker may only play an attack card of the same name as the one they previously played. Cosmic Mirror blocks the attacker's attack and reverses its effect onto the attacker. However, to stop this, the attacker may NOT play a Cosmic Mirror so that the reversed attack would bounce back onto the defender again!
You check for victory at the end of your own turn. If an attack has no valid target, the card must be discarded with no effect.
Example game
A typical round with two players
Anna has six planets; she is missing Mars and Neptune. She draws two cards, including a Neptune. As her first action she plays Neptune, as her second she plays an action card, then she ends her turn by discarding one card. She keeps Mars in her hand — she may place only one planet per turn, because two identical actions are not allowed.
Béla launches a Supernova against Anna's Neptune. Anna, however, responds with Cosmic Mirror. Béla has no second Supernova for a Breakthrough and cannot play Cosmic Mirror in this case, so the effect turns on him: he loses his Jupiter. Anna's system remains intact.
On Anna's next turn she plays Mars. She does not have the Glitch, and she has all eight planets — she wins the game.
Deck composition
Counts by number of players
The game is designed for 2–5 players.
| Card | 2 | 3 | 4 | 5 |
|---|---|---|---|---|
| Loading deck… | ||||
Strategy tips
For beginners and veterans
If you already have six or seven planets, you are the biggest target — keep at least one Atmosphere or Cosmic Mirror. Your system is openly visible, but your hand is secret: you can bluff with that too.
Don't rush Plotuh if you have a chance to draw a real planet soon — but if time is short, a Plotuh is better than an empty slot. Remember: only one can be in play at a time, swapping it is also an action, and it cannot be stolen with Gravity. If you have in hand the planet an opponent’s Plotuh is substituting, you can take the joker from them.
Wormhole is most worth it when you are missing only one or two planets. On Meteor Shower, name a type you yourself are missing. And sometimes passing is the strongest move.
You are not required to play your planets in the familiar order to the right of your Sun. They can be in complete disarray. The greater the chaos, the harder it is for your opponents to see which planet you are still missing.
Quick reference
Condensed onto one page
Turn structure — 1. Draw 2 cards (after an empty hand: 5+2). 2. Two different action categories in any order (or pass): placement / theft-draw / attack-destruction. 3. Discard 1 card. Hand limit: 7. If you acquire a planet first, you may place it as the second action; if you place first, an acquired planet cannot be placed this turn.
Victory — 8 different planets (one Plotuh may substitute for one), and no Glitch in hand or in play.
Victory — 8 different planets (one Plotuh may substitute for one), and no Glitch in hand or in play. Or: if the draw pile runs out, a closing round (the origin finishes their 2 actions, everyone else takes 1, the origin does not get an extra), then the most different planets win — without the Glitch; hands are revealed.
Defense — Atmosphere blocks · Mirror reverses · a second attack of the same name can Breakthrough.
Glitch — While you have it, you cannot win. Relocation: sacrifice one of your planets — cannot be defended.
Wormhole — Action (search). The planet found goes to your hand; placing it is a separate action.
FAQ
Frequently asked questions
Two Plotuhs — can I play both?
No. Only one can be in play at a time; the other stays in your hand.
Can I discard the Glitch?
Only together with a Black Hole, at the same time.
Can I defend against relocating the Glitch?
No. You can, however, defend against its first placement.
Wormhole: do I play the planet immediately?
The search puts it in your hand. If that was your first action, you may place it as the second. If you already placed a planet, only on your next turn.
Wormhole: do I play the planet immediately?
The planet/Plo-Tuh from the 6 cards goes to your hand. If Wormhole was first, you may place it as the second. You cannot place a planet as the first action — if you only want to place, pass, then place.
Gravitational Pull: can I place the stolen planet immediately?
The steal puts it in your hand. If the Pull was first, you may place it as the second. If you already placed a planet, only on your next turn.
Is swapping Plotuh an action?
Yes, it uses one of your two actions — whether you swap your own or claim an opponent’s. You cannot swap again in the same turn.
Can Plotuh be stolen with Gravitational Pull?
No. Plotuh in a solar system cannot be stolen with Gravity, even if it is substituting a named planet.
I've run out of all my cards?
At the start of your next turn you draw 5+2 cards.
I've run out of all my cards?
At the start of your next turn you draw 5+2 cards — unless the draw pile is already empty, in which case a closing round starts (you finish your turn, everyone else gets 1 action), then the game is scored.
What happens when the draw pile runs out?
The player who would draw finishes their turn (two actions + discard). Then clockwise, everyone else may take 1 more action, with no draw and no discard. The player who emptied the pile does not get an extra action. Then the game is scored: whoever has more different planets in their solar system wins. Everyone’s hand is revealed, and the program explains the winner. Defense still works during the closing round and does not use up that one action. Completing 8 planets still wins immediately.
Galactic trivia
Real trivia from the Solar System
Mercury: one of its days is about 59 Earth days, but one of its years is only 88 — so a year is shorter than two of its days.
Venus: it rotates in the opposite direction to Earth. A Venus day is longer than a Venus year.
Earth: the only known planet with liquid water on the surface — and so far the only one where we have found life.
Mars: home to the Solar System's largest known volcano, Olympus Mons — about 22 kilometres high.
A little more lore
Giants, rings and Plotuh
Jupiter: its Great Red Spot is a storm that has raged for centuries, larger than Earth. It has more than 90 known moons.
Saturn: its average density is less than that of water — if you had a large enough “bathtub”, it would theoretically float.
Uranus: its axis is tilted nearly 98 degrees; it almost “rolls” on its side. At its poles, day or night can last for decades.
Neptune: the Solar System's fastest winds have been measured here — up to 2000 km/h. One of its years is about 165 Earth years.
Plotuh: in memory of Pluto — in the game, the joker for the “missing slot”.