Sump
Original · a shared-air gamble for three to six
The air belongs to everybody. The gold belongs to whoever turns back.
Ready to play now.
A demonstration of Sump, played by the computer against itself.
Sump — playing itself
Ways to play
Alone, against the computer
Your own pace, no arranging anything. Take a move back whenever you like.
Play alone4 opponents, weakest first
- NervyReads the GAUGE and nothing else: a quarter of the tank gone and it turns, whoever is in the water and whatever the chambers pay. 1.5 banked a dive against its own kind at three divers, half its divers surfacing with anything, and never a chamber deeper than the second. The Counter takes it 200–0.
- The CounterReads the HERD. It walks the tank forward at the current company and pressure — the same company costs more next round than this one — and turns on the last round the air covers. 200–0 over Nervy at three divers and at five, 3.9 banked a dive, 94% of its divers surfacing with something. It still has no idea what the chambers pay.
- The AppraiserReads the PASSAGE. This dive’s chambers are drawn, so it finds the shallowest depth that pays as well as anything it can still reach and turns exactly there — early where the value plateaus at chamber five, late where it keeps climbing. 131–17 over the Counter at three divers (9.4 sigma), 140–16 at five, and the richest dive of any rung against its own kind: 5.0 banked, 99% surfacing.
- The Crowd-ReaderReads the OTHERS. It works out which divers a Counter or an Appraiser in their seat would seal BACK this round, prices the round’s air on the ones it expects to STAY, and aims for the depth that company can afford — so a room that is emptying is a tank about to be its own, and it presses on into the air the others left. 120–0 over the Appraiser at three divers (11.0 sigma), 121–0 at five, and 123 of 200 mixed foursomes. Against its own kind it banks 2.1 where the Appraiser banks 5.0, because a table of divers all waiting each other out is a table that drowns together: this is a nerve, not a solution.
Together, in the same room
3–6 players. One device goes round the table, or everybody plays off the same screen.
Play in the same roomOnline, at a table
A room code, joinable from anywhere. Pause tonight and pick it up next week from your device.
Play online
About
A flooded passage of twelve chambers, drawn fresh for every dive — none worth less than the one above it, the mouth worth one and the bottom worth twelve — and one tank that holds everybody’s air. Each round every diver still in SECRETLY seals one word: BACK, surfacing with the deepest chamber they crossed, or ON, breathing to cross deeper. The words land together. A chamber two divers leave in the same round is split between them, and the deep costs four times what the mouth costs, so the passage is bought rather than walked into. When the tank runs dry, whoever is still in loses everything they carry.
How it feels
- A commons with teeth
- Torchlight on the tank gauge
- Turning back while you still can
What the design is for
One tank, everybody’s lungs
The air is a single figure on a single gauge, and the round costs it a breath for every diver still in — one unit near the mouth, four at the bottom, charged after the backers leave. A diver two chambers behind you can drown your hand by staying in, and your staying in can drown theirs. Nobody drowns alone.
The deepest, not the sum — and shared if you are not alone
What you bank is the DEEPEST chamber you crossed, so every round in is a raise you have not cashed and BACK is the only cash. And a chamber more than one diver leaves in the same round is split between them, rounded down: turning back with the crowd is worth half of turning back a round before it. The only question in the sump is when, and the answer depends on everybody else’s.
Words sealed together
Every diver still in seals BACK or ON in secret, and the picks land together — the shelf’s simultaneous machinery, with the view carrying your word and who else has sealed, never what they sealed.
The dry tank keeps everything
When the air runs out mid-crossing, the passage keeps whatever the still-in were carrying. The surfaced watch their greed drown in real time; the drowned watch their own chips settle back to the sump floor.
Taught round by round
Six steps: the seal, the pressure, the bank, the shared chamber, the drowning round — and then the whole passage to yourself. Every step accepts only the word its own text asks for.
- Best at
- 5
- Kind
- Party
- Table
- Competitive
- Studio
- Board.game Originals
The opponents
Nervy
Reads the GAUGE and nothing else: a quarter of the tank gone and it turns, whoever is in the water and whatever the chambers pay. 1.5 banked a dive against its own kind at three divers, half its divers surfacing with anything, and never a chamber deeper than the second. The Counter takes it 200–0.
The Counter
Reads the HERD. It walks the tank forward at the current company and pressure — the same company costs more next round than this one — and turns on the last round the air covers. 200–0 over Nervy at three divers and at five, 3.9 banked a dive, 94% of its divers surfacing with something. It still has no idea what the chambers pay.
The Appraiser
Reads the PASSAGE. This dive’s chambers are drawn, so it finds the shallowest depth that pays as well as anything it can still reach and turns exactly there — early where the value plateaus at chamber five, late where it keeps climbing. 131–17 over the Counter at three divers (9.4 sigma), 140–16 at five, and the richest dive of any rung against its own kind: 5.0 banked, 99% surfacing.
The Crowd-Reader
Reads the OTHERS. It works out which divers a Counter or an Appraiser in their seat would seal BACK this round, prices the round’s air on the ones it expects to STAY, and aims for the depth that company can afford — so a room that is emptying is a tank about to be its own, and it presses on into the air the others left. 120–0 over the Appraiser at three divers (11.0 sigma), 121–0 at five, and 123 of 200 mixed foursomes. Against its own kind it banks 2.1 where the Appraiser banks 5.0, because a table of divers all waiting each other out is a table that drowns together: this is a nerve, not a solution.
Achievements
0 of 5 earned
First to the Surface
Win a dive of Sump.
The Whole Chamber
Win with a haul you shared with nobody — no other diver left that chamber in your round.
The Deep Half
Win having surfaced from the seventh chamber or deeper.
Last Out
Win having turned back with the passage to yourself — nobody else still in.
Twice Their Haul
Win with double the runner-up’s bank.
Key art
Key art — Board.game art system
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