The objective of the game is to find the required items to perform a conjuring and take them to the conjuring room to win the game. The items you need to find are scattered across the map.
In Survive a Nightmare there are two types of specters, "Ghosts" and "Demons", if you have an encounter with a specter your panic level will increase respectively: Ghost +1 panic point, Demon +2 panic points. If your panic level reaches "5" you will suffer a panic attack and lose the game.
Each player turn has 2 phases, "Player's" phase and "Specters" phase, on the player's phase you have 4 action points, which can be used to move your character marker to an adjacent room, search for an item (rolling a die), use an item (each one has a different effect), activate fuse boxes, use a portal or to activate the rewards track which grants you additional items.
After ending a player's phase, the specter's phase begins. The active player will roll the die twice and resolve a spawning of specters across the rooms. When the specter's phase ends, the active player's turn ends. The game takes place by alternating turns between each player, until one player completes the conjuring and wins the game. Survive a Nightmare has a solo mode and a cooperative mode.
-description from designer