Investigation Board — The Sinking City 2's Optional Case System

The investigation board is where The Sinking City 2 splits from a pure survival horror game and remembers its detective roots. It’s a case-tracking system — a physical (or at least in-world) board where you pin clues, connect evidence, and solve cases that the game never actually forces you to touch. That last part matters. Frogwares has been clear: investigation never hard-gates your progress. You can blaze through Arkham with a shotgun and sheer stubbornness, never once opening the board, and still reach the end.

But you’d be making life harder for yourself. Much harder, probably.

How It Works

Based on the demo and preview coverage, the investigation board functions as a hub for every clue you discover while exploring flooded Arkham. Pick up a waterlogged journal entry, examine a corpse, overhear a conversation between NPCs at a speakeasy — these fragments appear on the board as individual evidence nodes.

The core loop is connection. You drag clues together, looking for relationships: a witness statement that matches a shipping manifest, a symbol carved into a wall that appears again on a piece of cargo. When you link the right pieces, the board resolves a deduction — your character draws a conclusion, and that conclusion unlocks something tangible.

What it unlocks varies. Sometimes it’s an alternate route through a flooded building that bypasses a nasty Deep One nest. Sometimes it’s a piece of lore that fills in Arkham’s backstory. Other times, reportedly, it feeds directly into the progression system — solving cases grants upgrade materials or unlocks build options you wouldn’t have access to otherwise.

The board appears to organize cases by district or story thread, with tabs or sections keeping things manageable. If you’ve played the first Sinking City, the concept will feel familiar, though Frogwares has reportedly streamlined it. Less backtracking to random map points, more working with what you’ve already found.

Why It Matters

Here’s the tension that makes the investigation system interesting from a design standpoint: it’s optional, but the game is balanced around survival horror scarcity. Ammo is thin. Healing items don’t grow on trees. The flood keeps rearranging the map. If investigation unlocks alternate routes that skip combat encounters, or rewards you with crafting materials and upgrade access — then engaging with it isn’t just a lore bonus. It’s a survival strategy.

Think of it as a difficulty dial that the game never labels as one. Players who investigate thoroughly get more tools, more paths, more breathing room. Players who skip it get a leaner, meaner, more desperate experience. Both are apparently viable. Neither is wrong. Frogwares hasn’t detailed whether specific story beats require investigation or simply benefit from it, but the messaging has been consistent: no hard gates.

That philosophy also shapes how exploration feels. Knowing that every odd detail might become a clue changes the way you move through a room. You stop speed-running past bookshelves. You actually read the graffiti. The sanity system may punish you for lingering in dark places, but the investigation board rewards you for it — a nice push-pull that should keep each district visit tense.

Tips for Working the Board

Pick up everything. Even if a clue seems irrelevant now, it might connect to a case three districts away. Inventory space for evidence appears to be separate from your resource inventory, so there’s no reason to leave clues behind.

Check the board after each major location. It’s easy to forget about it during tense exploration sequences. Getting into the habit of opening it between areas means you’ll catch connections while the context is still fresh.

Don’t force connections. If two clues don’t link, they don’t link. Trying every combination is a waste of time — the board seems designed so that correct connections make logical sense based on what the evidence actually says. Read the clue text.

Use solved cases to plan your route. If a case solution reveals an alternate path through a flooded district, take it. The detour almost always saves you resources compared to fighting through the default route.

Pair investigation with thorough exploration. The best clues reportedly come from hard-to-reach spots — rooms behind locked doors, items hidden behind flood debris, objects that require specific tools to access. If you’re already exploring carefully for supplies, you’re already doing half the investigation work.

The investigation board won’t save you from a Slither lunging out of the dark water. But it might tell you which streets the Slithers avoid — and sometimes that’s worth more than a full magazine.