Mysterium has two expansions, and you should buy Hidden Signs first. It adds 42 new vision cards and new suspects, locations and objects with no new rules, so it makes every game fresher without changing how you play. Buy Secrets & Lies second, when your group wants a harder challenge.
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Both expansions need the base game. We’ve played base Mysterium but not the expansions, so this ranking comes from Libellud’s rules, the box contents and published reviews, and we say so where it matters.
| Expansion | Year | What it adds | New rules? | Ranked |
|---|---|---|---|---|
| Hidden Signs | 2016 | 42 vision cards, plus new suspects, locations and objects | No | 1st |
| Secrets & Lies | 2017 | 42 vision cards, new suspects, locations and objects, and story cards that replace objects | Yes, story cards | 2nd |
1. Hidden Signs Is the One to Buy First
Hidden Signs is more Mysterium and nothing else. It doesn’t change a single rule, which is exactly why it’s first.
The original 2016 box has 42 new vision cards and 18 new psychic cards with matching ghost cards: six characters, six locations and six objects. That’s 78 cards in all, according to Opinionated Gamers’ Hidden Signs review. The current printing has eight of each type, and its official rules say plainly that it adds no rules.
The new vision cards are the real value. The ghost only ever works from a hand of seven, and 42 more paintings in the deck means more ways to say what they mean. The new suspects and locations matter once your group starts recognizing the base cards.
Worth knowing: Opinionated Gamers recommended Hidden Signs to fans but called its price a bit steep for a box of cards. It’s the right buy once your group has played the base game enough to see the same cards come around.
Check Mysterium: Hidden Signs price on Amazon →
2. Secrets & Lies Adds a New Kind of Clue
Secrets & Lies is the one that changes the game. Along with new suspects, locations and objects, it adds story cards, which you can play in place of the objects.
A story card is an event rather than a thing: something that happened just before the ghost died and might explain why they were killed. The original 2017 box has 18 of them, according to the Secrets & Lies BoardGameGeek entry. The current printing has 32 story cards, a story progress board and 42 vision cards, according to Libellud’s Secrets & Lies rules.
What changes: pointing someone to “the knife” with a painting is hard. Pointing them to an event, like a quarrel or a secret, is harder, because the ghost has to suggest a whole story.
Who it’s for: groups who find the base game too easy, and ghosts who enjoy the challenge. For a new group, it’s an extra layer the base game doesn’t need.
It doesn’t add players. Mysterium already plays up to seven, and neither the rules nor the listings mention more.
Check Mysterium: Secrets & Lies price on Amazon →
Which Edition of the Expansions?
Both expansions have been reprinted for Mysterium’s 2025 edition, with slightly different card counts: eight of each new type instead of six. If you’re buying both the base game and an expansion, buy the same edition of each so the card backs and numbers match.
The 2025 base game has a few other changes too, like three candle markers in place of the crows. Our Mysterium versions guide covers which base box to get.
Do You Need an Expansion at All?
No. The base game has 84 vision cards and 18 of each target type, which is plenty for many games. We rate the base game 4/5 Bamboo and 4/5 Pandas in our Mysterium review.
An expansion makes sense once two things are true: your group plays often enough to recognize the cards, and you still want more Mysterium rather than a different game. If your group is new, put the money toward the base game and learn the rules first with our Mysterium rules guide.
If you’d rather have something smaller and faster, Mysterium Park is a separate standalone game, not an expansion.
Frequently Asked Questions
How many Mysterium expansions are there?
Two in English: Hidden Signs (2016) and Secrets & Lies (2017). Both were reprinted for the 2025 edition. Mysterium Park and Mysterium Kids are separate standalone games, not expansions.
Which Mysterium expansion is best?
Hidden Signs, for most groups. It adds 42 vision cards and new suspects, locations and objects with no new rules. Secrets & Lies is better for groups who want a harder game.
Are Mysterium expansions worth it?
Yes, once your group has played the base game enough to recognize the cards. New groups don’t need one yet; the base game has 84 vision cards.
Do you need the base game for the Mysterium expansions?
Yes. Both Hidden Signs and Secrets & Lies require the base game.
What are story cards in Mysterium?
Story cards come in Secrets & Lies and can replace the object cards. Each one is an event that happened before the ghost died, so the ghost has to hint at a story instead of a single object.
Does Secrets & Lies add more players?
No. Mysterium already plays up to seven players, one ghost and six psychics, and the expansion doesn’t change that.