About Lantern Deep
Lantern Deep is a free browser deduction puzzle that crosses Minesweeper with a dungeon crawl. Instead of counting mines, every number on the board is the total power of the monsters touching it, so a 4 can be a single Wraith or a Moth beside a Ghoul, and the fun is proving which. Fighting is not failure here: every monster is a cost you choose to pay in lantern oil, and the embers it leaves are how you grow. The pressure comes from the Warden, a boss at the top of each chamber that only wakes when every tile around it is open and costs a fixed amount of oil to break. Spend too freely and you stand in front of it with an empty lantern. Every chamber is generated from a seed and then checked by a solver before you see it: the game plays the chamber itself using only what can be proven, so no chamber ever needs a guess. You can still guess, and Proof records how often you did. There are two modes. The Daily Crypt is four chambers, the same for every player in the world, with one attempt a day, a time bonus on a full clear, and a spoiler-free square grid to share. The Endless Catacombs run forty chambers long with rising Wardens and saves after every move, so a run can last a week. Lantern Deep has no ads, no purchases and no account wall, plays on phones, tablets and desktops with full keyboard support, and honours your reduced-motion setting.
How to Play Lantern Deep
Every chamber is a grid of closed tiles hiding monsters with a power from 1 to 9. An open tile shows a number: the total power of the living monsters touching it. Tap a tile to open it. If a monster is there you fight it, which burns oil equal to its power and earns that many embers; a monster stronger than your remaining oil puts the lantern out and ends the run, but exactly enough is enough. The Warden sits near the top of the chamber and wakes once every tile around it is open; breaking it costs the oil printed on it, so keep that much in reserve. Break it and take the stairs: your embers become levels, and the lantern refills larger for the next chamber. Chests are always visible: each holds loot, which pours oil into the lantern and never counts in a number, or a Mimic, a monster that does, and the numbers always tell you which. A Shade is a monster that hides every number beside it behind a ?; slay it and the numbers come back. Hold a tile, or turn on Mark, to note what you have worked out.
Lantern Deep Tips and Strategy
- A number is a sum, not a count. A 3 next to one closed tile is a single power-3 monster; a 3 next to three closed tiles could be three Moths or one Ghoul, so look for the neighbour that settles it
- Watch the Ledger. When a power's chip reads zero there are none of it left in the chamber, and every number around the board just became easier to read
- Chests are always in plain sight, and each is loot or a Mimic. Loot never counts in a number and a Mimic always does, so the numbers around a chest, with the Ledger's Mimic chip, tell you which before you touch it
- A ? is a number a Shade is hiding: at least one closed tile beside it is a Shade. Work from the numbers you can still read, slay the Shade, and every ? it covered turns back into a number
- Exactly enough oil is enough. A fight that costs every drop you have still wins, and breaking the Warden on your last drop is a Last Flicker
- Keep the Warden's price in reserve. The tick on the oil bar marks it; once you drop below it, only the oil flask can bring you back
- Open the Warden's ring before you spend freely. Its guards are always the chamber's two weakest monsters, so the cheapest proven fights there are rarely wasted
- Every fight lowers the numbers around it, and an empty tile that falls to zero opens its neighbours, so a well-chosen kill can light half the board
- Hold a tile to mark what you have proven. A marked tile asks before it opens, which turns a slip of the thumb into a second chance
- Sure-footed chambers, cleared without a single blind tap, pay a bonus of 50 points times the chamber number, and they are what your Proof percentage measures
Lantern Deep FAQ
Is Lantern Deep free to play?
Yes. Lantern Deep is completely free with no ads and no in-app purchases. It runs in any modern browser on phone, tablet or desktop, and once the page has been cached it plays offline.
How is Lantern Deep different from Minesweeper?
In Minesweeper a number counts the mines around it. In Lantern Deep a number is the total power of the monsters around it, and touching a monster is not an instant loss: it is a fight that costs oil equal to its power. You choose which fights to take, keep enough oil for the chamber's Warden, and turn the embers you earn into levels that grow your lantern.
What are Shades, Mimics and chests?
From the second chamber on, every chamber hides Shades and chests. A Shade is a monster that turns every number beside it into a ?, so you have to work around it; slay it and those numbers come back. A chest is always visible and holds either loot, a pour of oil that never counts in any number, or a Mimic, a monster whose power counts like any other. The chamber is checked before you see it, so whether a chest is a Mimic can always be worked out from the board.
Will I ever have to guess?
No. Every chamber is checked before you see it by a solver that plays it using only deductions, and a chamber that cannot be finished that way is thrown away. On the Daily Crypt and the first seven Endless chambers the solver also checks that the oil you arrive with is enough. After that, a chamber is guaranteed solvable without guessing, but budgeting your oil is up to you. You may still guess if you want to, and the Proof stat shows how often you did.
Does everyone get the same Daily Crypt?
Yes. The four Daily chambers are built from the day's number by a deterministic generator, so every player gets exactly the same crypt. You get one attempt a day; after it, you can replay the crypt as practice, which posts nothing.
How is the score calculated?
Each monster slain is worth its power squared times four plus the chamber number, each Warden is worth 100 times the chamber number, and a Sure-footed chamber, cleared without a blind tap, adds 50 times the chamber number. A full Daily clear also earns two points for every second under eight minutes.
What happens if my lantern runs out?
A fight with a monster stronger than your remaining oil puts the lantern out and ends the run. A fight that costs exactly what you have still wins. If the Warden's price ever falls out of reach, the run ends too. Every chamber you finished still counts toward the score.
Can I play with a keyboard?
Yes. The arrow keys move between tiles, Enter or Space opens one, M toggles Mark mode, the digit keys and ? place marks, L and X mark a chest as loot or a Mimic, S marks a Shade, Backspace clears one, and Escape pauses. Every tile announces its state to screen readers.
