Travel along any path connected to your current location. Uncleared locations hold an encounter; cleared locations can be crossed freely. Buying and selling are available only while visiting the First National Grocery, which can be revisited. Three clues are hidden at random among the encounter locations each run; clearing a location reveals any clue it holds. Find all three to open the vault beneath Marsh Refining Co. A Tarnished Harbour Key is also hidden in one encounter’s loot; carry it in the satchel to The Sealed Boathouse to open it.

Human attacks roll 3 dice. Each 4–6 deals 1 damage. Armour is a shield: it soaks up damage point for point until it is used up. Occult attacks ignore it. Each investigator acts once, then living enemies use the next move shown on their sheets. Their patterns advance after each action. Enemies with a charge bar gain +1 charge from the moves marked “+1 charge”; at three, their next action is their power move, which resets the bar. Other enemies that gain charge add +1 damage to their next attack. Some enemies Mark an investigator; their allies can punish a Marked target for extra damage — defeat the marker first to break the combo. Hindered investigators roll one fewer die on their next attack; bound investigators lose their next action. Sealed enemies retain their charge but cannot act until the seal wears off. Built-in armour and a Protective Coat (+2) refill at the start of every encounter; Take Cover (on each investigator’s sheet) and Ward add 2 armour that lasts until the next round and is used first. Take Cover uses that investigator’s action.

Each investigator has one skill charge bar that carries between encounters. Most charge +1 for each 1 they roll, including rerolls and investigation rolls; Sister Agnes charges on each 1 or 2 and +1 more for any double, and Eliza Marsh on a Hit or Perfect Strike. Each skill has a charge cost; tap a skill once its cost is charged to spend that charge and your action.

Holy Gift: needs 2 charge; Sister Agnes passes all her skill charge to another investigator (anything their bar can’t hold is lost). Holy Might: 4 damage ignoring armour (all of Sister Agnes’s attacks ignore armour) and reduce the target’s next attack by 1. Eldritch Bolt: 3 damage ignoring armour. Crimson Seal: roll one red die; on 4–6, deal 2 damage to every enemy, ignoring armour, and make survivors miss their next attack. On 1–3, the seal half-forms: 1 damage to every enemy, ignoring armour. Eldritch Bolt and Crimson Seal each cost 3 charge; Frank Harker’s Blast Bomb costs 5 (Focused: 8 damage to one enemy, or Wide: 3 damage to every enemy); Sister Agnes’s Holy Might costs 4. The other investigators’ weapons and skills are listed on the selection screen. Skills marked “free” do not use the investigator’s turn; skills that help an ally let you choose who. Eliza Marsh’s Barbed Harpoon uses no dice: tap as the sweeping line crosses the bar — the gold band is a Hit (2 damage), the narrow centre a Perfect Strike (2 damage and Bleed: 1 damage a turn for 3 turns; another Perfect Strike refreshes it rather than stacking).

Each victory restores 3 health to every living investigator. Death is permanent: an investigator reduced to 0 health is dead, cannot be healed, and sits out every later encounter. Only a Reanimating Reagent from the First National Grocery brings them back, at full health, outside combat and only while someone still lives. If every investigator dies, the run is over.

The satchel holds 5 unequipped items (6 with the Oilcloth Haversack from Osborn’s in Chapter 2); the Tarnished Harbour Key doesn’t take a slot. When full, swap out an item or decline the incoming item. Each investigator has two equipment slots: one weapon and one protective item. Equipping a weapon replaces the current weapon. Equipped gear takes no satchel space. Loot can be equipped directly; if the satchel is full, choose what to discard before storing a replaced weapon. Using a supply in combat costs the selected investigator’s action. A Bandolier is readied from the satchel in combat and costs that investigator’s action; their next attack adds 2 blue Boon dice that hit on 3+ (with the Barbed Harpoon, that strike applies Bleed even on a miss). A Firebomb must be equipped to an investigator (it takes its own slot, one per investigator, and can’t be equipped mid-fight); it then appears on their sheet as a single-use throw at the targeted enemy: 2 damage that ignores armour, then Burn for 3 rounds (1 damage at the start of each enemy round; another Firebomb refreshes it). First-aid kits restore 4 health to a living investigator. Refreshing starts a new run.