Find your rulebook and reference guide.
Open your rulebook to page 4.
1. Place the game board.
2A. Gate tokens: Randomize the stack face down. Place them on your table.
2B. Clue tokens: Randomize them and place on table. You may either place them face down in a small pile or leave them in a small bag and choose later.
2C. General token pool: Place Health, Sanity, Improvement, Travel Tickets, Eldritch, Mystery, and Rumor tokens in a common area on the table. I leave them in small craft bags until they’re needed later in the setup and game.
3. Choosing investigators: Separate character cards from ancient ones. Pick your characters. Decide which investigator will be the Lead Investigator and assign the Lead Investigator to him/her Place each investigator token on the game board as indicated on their respective sheet.
4. Starting possessions, Health and Sanity tokens: Each investigator gets a number of Health and Sanity tokens equal to the number printed on their cards. Each investigator is given assets or spells as listed on their sheet.
5. Determine the Ancient One. Place the sheet on the table. Follow the Setup instructions on the AO sheet.
6. The Monster cup: All non-epic monsters are collected in a bowl, cup, or bag. I use a zippered canvas bag originally from an old headset. Do not place the Epic Monster tokens in the Monster cup.
7A. Separate Cthulhu Mystery, Research, and Special encounter cards from your deck. Those not corresponding to the chosen Ancient One is returned to the game box and will not be used.
7B. Shuffle all Expedition Encounter cards into a single deck regardless of the card back.
7C. Shuffle Spell and Condition cards into two separate decks. Place decks face up, with the top card’s name and artwork visible.
7D. Set Mythos cards aside. Separate all other cards into decks by card back and shuffle each deck (Other World and Encounter cards)
8. Build the Mythos deck. Read the Mythos Deck section on the Ancient One sheet.
9A: Find and place the reference card that corresponds to the number of investigators.
9B. Place the Doom token on the space of the Doom track listed on the chosen Ancient One sheet.
9C. Place the Omen token on the green space (comet) of the Omen track.
9D. Place the top four cards of the Asset deck face up on the four empty slots of the reserve on the game board.
9E. Spawn the number of Gates indicated on the Reference card. Remember to draw one random Monster token from the Monster cup and place it on the same space.
9F. Place the Active Expedition token on the space that corresponds to the illustration on the back of the top card of the Expedition deck.
9G. Spawn the number of clues on the Reference card.
9H. Draw one Mystery card and place it near the Ancient One sheet. Resolve any “When this card enters play” effects.
Finally, make sure you read Fantasy Flight Games FAQ.