Fathom – Not Your Average Day at Sea

In the coastal town of Fathom, nestled between steep island peaks and clear, sunlit waters, a familiar chapter in marine research is coming to a close. After nearly fifty years of leading deep-sea exploration, Nautilus Leclerc is finally retiring. His work has paved the way for generations of ocean study, but now the sea is open to new eyes and eager minds.

With Leclerc stepping down, up to four new marine biology teams are ready to take the plunge. Each one is led by a determined researcher, keen to uncover the secrets of the ocean floor, document new species, and build on the work Leclerc began. The goal? To earn the title of Fathom’s next great explorer.

👥 2-4 players, ages 10+
⌛ Playing time: 45 minutes
📝 Designer: Dan Helfer
🎨 Artwork: Ekaterina Boguslavskaya

🏢 Publisher: Paper Fort Games (review copy provided)

Gameplay Overview

The game takes place over six rounds, with each player managing their own ocean board. You’ll use a ship and submersible to explore, discover marine species, and place tiles in ways that earn you points. The player with the most points at the end of the game wins.

Each player starts with a full set of tools: an ocean board, a ship, a submersible, a tile bag, and a player console. In the middle of the table sits the sonar board, which holds shared discovery tiles and bonus tokens. Throughout the game, you’ll place species tiles onto your board and flip them to mark them as discovered. How you arrange them and which species you focus on will shape your final score.

Each round has three parts: the ship phase, the sonar phase, and the submersible phase.

In the ship phase, players draw three tiles from their bag and can place up to two of them onto their board. These tiles go either underneath or beside their ship. One of the tiles directly beneath the ship can then be flipped to reveal a discovered species. Any tiles you didn’t use go to the sonar board, placed in your assigned segment.

Then it’s time for the sonar phase. Players take turns repositioning their sonar beams, which re-divides the sonar board into equal sections. Any empty spaces on the sonar board are filled with bonus tokens. These tokens can be picked up in the next phase and used to unlock extra advantages, such as an extra move, an extra action, or flipping a final tile before scoring.

Finally, in the submersible phase, each player takes up to four actions using their submersible. You can place tiles from your sonar segment onto your board, flip tiles that are next to your sub, pick up any bonus tokens in your segment, or move your sub around the board. When this phase ends, tile bags are passed to the next player, turn order rotates, and the game moves to the next round.

Scoring is based on which species you discover and how you place them. Each of the four core species has its own scoring system. Coral gives points based on how many tiles of the same colour are grouped together. Schooling Fish score for forming groups with at least six fish icons. Sea Cucumbers are scored competitively, with the player who has the most earning the most points. Crustaceans score for being next to coral, and they’re even more valuable if they’re touching coral of different colours. As you play more games, you’ll explore the different expeditions, each of which introduces two new types of tiles with their own unique rules and ways to score.

At the end of the sixth round, any tiles that are still face-down are removed. Everyone then adds up their points from discovered tiles and any points of interest tokens. The player with the highest total becomes Fathom’s new leading explorer, ready to carry on Leclerc’s legacy.

Game Info

Fathom is a mid-weight tile placement game designed for 2 to 4 players, with most sessions lasting around 45 minutes. It’s recommended for players aged 10 and up. This is the first published design from Dan Helfer and is released by Paper Fort Games, a small independent publisher based in the UK. You might know them from their earlier title Cosmoctopus, which was funded through Kickstarter a while ago.

The theme puts you in charge of a marine research team, exploring the depths and competing to carry on the legacy of the great Nautilus Leclerc. And while there’s no actual diving gear involved, you’ll still be making some deep decisions along the way.

Components, Production and Artwork

Let’s talk table presence, because Fathom has plenty of it. The first thing you’ll notice is the clean and colourful design. The artwork, created by Ekaterina Boguslavskaya, captures the underwater theme in a way that’s vivid without being overwhelming. Every piece has its own look and feel, but it all comes together in a way that’s easy on the eyes and practical during play.

From the ocean boards to the tokens and tiles, the game is designed to stay readable even when things get busy. Icons are clear, species colours are distinct, and the board layout gives each player enough space to do their thing without crowding. It’s thoughtful design, and it shows.

Each player has their own ocean board, which represents a section of the seafloor. These boards are laid out with zones for tile placement and connecting corners where the submersible can travel. There’s also a personal console with sliders to help you track your available actions during each phase. These sliders feel intuitive and make it easy to manage your turn without checking the rulebook constantly.

In the centre of the table, there’s a sonar board where players place unused discovery tiles and collect bonus tokens. This board is divided into segments each round using sonar beam markers, which determine which section belongs to which player. It’s a clever bit of design that looks good on the table too.

Each player also controls a ship and submersible, both mounted on plastic stands so you can still see the tiles beneath. These pieces are simple but fit the underwater theme nicely and are easy to move around the board.

Inside the box, you’ll find 72 discovery tiles that form the core species: coral, schooling fish, sea cucumbers, and crustaceans. There are 48 additional tiles introduced via the expedition system. The game also includes four expedition tuckboxes, each with two unique tile types and rules. There are points of interest tokens that vary by expedition and add some hidden scoring opportunities, and bonus tokens offering one-off effects like tile flips or extra movement. The sonar board, round tracker, and player order tracker help keep the game structured. Each player gets their own tile bag, useful both during play and for storing components between games. To make everything easy to reference, the game includes scorepads, reference cards, and species guides.

Setup isn’t too complicated once you’re familiar with the pieces, but it’s worth mentioning that Fathom does take up a fair bit of table space. With three or four players, you’ll want a medium-to-large table to give everyone some breathing room. That said, the layout is neat and organised, and it avoids the cluttered feeling some tile games can suffer from.

Clarity and Rulebook Quality

The rulebook does a good job of guiding players through their first game. It opens with a short bit of story to set the tone, then moves quickly into a clear explanation of the components and phases. Each phase of the game is explained with examples and diagrams, making it easier to understand how things flow.

Important concepts like zones, corners (or “vertices”), and sonar segments are introduced early and used consistently. That makes it much easier to get through your first game without flipping through pages.

There are also clear setup instructions for each of the four expeditions. You’ll find visual aids, icons, and summaries throughout the rulebook, which really help you avoid mid-game confusion. It’s the kind of rulebook that’s friendly to both casual players and strategy fans, and that’s not always easy to pull off.

Gameplay and Mechanics

At the heart of Fathom is a balance between tile placement and action management. You only get so many things you can do each round, so every decision feels like it matters. The game is played over six rounds, which go by faster than you might expect. That time pressure brings a bit of quiet tension, even though you’re mostly focused on your own board.

You’ll need to flip tiles to their discovered side before they’ll count, which makes placement alone only half the puzzle. You’ll place tiles face-down, knowing what they are, and then use your ship or submersible to flip them later, which means you need to think a few steps ahead. It’s easy to end up with good tiles in the wrong spots or too many face-down tiles that you won’t have time to flip.

The ship gives you a bit of control since you can place it anywhere at the start of a round. But its effect is limited: you can only place tiles under or next to it, and only the one directly beneath it can be flipped during the ship phase. That can feel restrictive if you don’t plan ahead.

The submersible is more flexible but also more demanding. You get four actions per round, which at first feels generous, but they’re quickly used up by moving, flipping, placing tiles, or collecting bonus tokens. Getting the most out of each round means carefully weighing your options and sometimes letting go of an opportunity in favour of a better one.

Bonus tokens don’t score points directly, but they offer effects that can stretch your turn in useful ways. You might get to flip a tile, move your submersible an extra space, or perform one final tile flip after the last round ends. Grabbing them costs one of your submersible’s four actions, though, so it’s not always worth going after a lone token. Timing and positioning really matter here.

And while it’s tempting to fill your board with tiles and aim for perfect groups, none of that matters if you can’t flip them in time. The game often comes down to efficiency, not ambition.

Expeditions and Variety

Every game of Fathom is played using one of four expeditions. These aren’t just minor tweaks. Each expedition comes with two unique tile types, new rules, and a dedicated guide. Some introduce new species, while others bring in things like camera icons, jellyfish chains, or even sharks. They subtly shift how you approach scoring, planning, and movement.

Point of interest tokens also vary depending on the expedition, offering new effects or scoring opportunities each time. The result is a core gameplay loop that stays familiar while giving you something new to explore every session.

Player Interaction and Pacing

Although most of the gameplay happens on your personal board, there’s still a layer of interaction. The sonar board connects all players through shared tile placement and competition for bonus tokens. It’s not cutthroat, but there are definitely moments when you’ll block someone or lose a tile you hoped to grab.

Because the game only lasts six rounds, you don’t have much time to recover from missteps. You can’t afford to waste actions, and if you focus too much on building without flipping, you might end up with a lot of tiles that don’t score. Timing becomes especially important in the final round, where one well-planned action can make the difference.

Final Thoughts

The game does a great job blending accessible gameplay with meaningful choices. It’s not hard to learn, especially after your first round, but the decisions still feel rewarding. There’s a tension that builds as the game progresses. Not from player conflict, but from your own puzzle and time pressure. It’s a game about doing a lot with a little.

If you’re into tile-laying games that reward planning and spatial awareness, Fathom will likely click with you. It reminds us a little of Cascadia or Calico, but with more movement, more structure, and a clever action economy that forces tough calls. And with four expeditions offering different setups and scoring styles, there’s plenty to come back to.

That said, it’s not for everyone. The action limits can feel tight, especially if you’re the kind of player who wants to optimise everything. And while it’s not a complex game, it’s easy to place more tiles than you’ll have time to flip. That can catch new players off guard in their first game, but once that clicks, the rest flows smoothly.

Fathom delivers a well-thought-out puzzle that plays out just the way we like: calm on the surface, and quietly tense underneath.

📝 We received a review copy from Paper Fort Games.