Nemesis: Lockdown

The game board is placed centrally, with the basic side (red arrow) used for the first game. Special tiles like the Isolation Room, Repository, Backup Power Supply, Elevator, Main Gate, and Rover are placed as indicated in the rulebook. Room 2 and Room 1 tiles are shuffled face down and dealt to their respective slots, with remaining tiles returned to the box. Underground Exploration tokens are shuffled and placed face down on unrevealed room tiles. Power tokens are shuffled and three are dealt to section slots, one on the Elevator token, with blue side up for 1 or 2, and red unpowered side up otherwise. CSS tokens are shuffled and dealt face down onto the Time Track. The Night Stalker Laboratory board is placed with five egg tokens in the nest slot, and three shuffled Night Stalker Weakness cards are dealt face down, with the first revealed. The Intruder bag is prepared with one blank, four larva, one creeper, one queen, and three adult tokens, plus one adult per player, with remaining tokens set aside. Item, Crafted Item, Night Stalker Event, Night Stalker Attack, Contamination, Serious Wound, and Computer Action decks are shuffled and placed, with the top Computer Action card revealed (reshuffling Lockdown cards). Game tokens and dice are placed nearby. The Time token is placed on the 15th space of the Time Track, red inactive side up. Players receive help cards, inventory card holders, contingency and Night Stalker reference cards. Objective decks (Corporate and Personal) are prepared, removing cards exceeding player count, then one from each is dealt to each player, kept hidden. Contingency tokens are shuffled, one dealt face down to each player, and one placed face down on the active contingency slot next to the Alert Room. Character Draft cards are shuffled, two dealt to each player, who choose one and shuffle the other back. Each selected character receives their board, knowledge token, action card deck, starting items, and miniature, placed in their starting room (Isolation Room for Survivors, Repository for Facility Workers). Knowledge tokens are placed on space 3 of the Knowledge Track (or space 1 for Facility Workers). The First Player token is given to Player 1.

The primary objective for each player is to successfully fulfill the conditions outlined on one of their two secret objective cards. These objectives can vary greatly, from personal survival to corporate mandates or even the elimination of specific intruders. In addition to completing their objective, players must also ensure their character survives the perilous Martian facility, which includes not being infected and successfully passing any active contingency. Escaping through a CSS pod, the bunker, or being in the isolation room when the game concludes are all valid ways to survive. If a player meets all these conditions, they achieve victory.

Gameplay unfolds in a series of rounds, each comprising two distinct phases: the Player Phase and the Event Phase. During the Player Phase, all players simultaneously draw action cards up to a hand limit of five. If a player's deck is depleted, their discard pile is shuffled to form a new action deck. The First Player token then passes clockwise. Starting with the new first player, players take turns performing two actions. Actions can include movement (cost 1) to an adjacent room via a corridor, careful movement (cost 2) to control noise placement, picking up heavy objects (cost 1), trading items with other players in the same room (cost 1), crafting items (cost 1) by discarding two item cards with matching component symbols, or engaging in combat (shoot or melee attacks). Players can also use actions from their action cards, item cards, or room tiles, each with its own cost and effect. The Computer Action card on the board can also be used by a powered character in a room with a computer in that section. Once a player passes, they are out of the turn sequence for that phase. The Player Phase continues until all players have passed. The Event Phase then begins, where players check for CSS pod launches, advance the time token, remove noise tokens, intruders attack characters in their rooms, and event cards are drawn and resolved. Finally, one intruder token is drawn from the bag, and its corresponding effect is resolved. This cycle of Player and Event Phases continues until a game-ending condition is met.

Victory is determined during a specific Victory Check phase at the end of the game. To win, a player must have successfully completed their chosen secret objective. Additionally, they must have survived the ordeal in the facility, meaning they are not infected and have successfully passed any active contingency. Survival can be achieved by escaping in a CSS pod, reaching the bunker, or being securely locked in the isolation room when the game concludes. If a player meets all three of these criteria—objective fulfilled, not infected, and successfully survived—they are declared the winner. In competitive play, only one player can win, even if multiple players meet the conditions. In cooperative modes, all surviving players who meet their objectives win together.

The game can conclude under several critical conditions. Firstly, if the Time token advances to the final slot (marked 'S') on the Time Track, the facility is purged by corporate forces, resulting in the death of all characters not in the Isolation Room, regardless of the active contingency. Intruders, however, survive this event. Secondly, the facility can auto-destruct and explode if the Time token passes the red Auto-Destruction token, or if 13 Fire markers or 11 Malfunction markers are present on the board. In this scenario, all characters in the facility (including those in the Isolation Room) and all intruders (including the Queen) die. Thirdly, if only one living character remains in the facility (excluding those who used the Isolation Room earlier), the game ends immediately. If any of these conditions are met, and at least one character has survived (either in the Isolation Room, safe in the Bunker, or evacuated in a CSS Pod), the game proceeds to the Victory Check to determine the winner(s).