The Antarctic Expedition

The short Lovecraft novella At the Mountains of Madness is a popular source text for many, many custom expansions, so much so that even Fantasy Flight Games are getting in on the act. Whilst the same expedition is also available in more extensive detail in the Door To Saturn expansion (also found on this site), this expansion – one of the first custom expansions for Arkham Horror – has the advantage of brevity of construction. One need only print the board and the encounters pdf to use it.


1. Making Preparations

Shuffle the Preparation Encounters, draw one of them and place the expedition token on the location indicated on the card. After having an encounter at that location, an investigator may follow the listed instructions, or discard 1 gate trophy, 5 toughness worth of monsters or$10 to take the Expedition Token. Once an expedition token has been claimed return the card to the box, then place a new Expedition Token on the board at the next listed location. Note that Expedition Tokens cannot be claimed whilst a Gate is in a location. The gate must be closed (or sealed) before the token can be claimed.

2. The Expedition

Once the preparations have been completed any investigator is in Arkham may start the expedition by moving to the Polar Voyage from the River Docks during the Movement Phase. On subsequent turns, the investigator should move to the next location in the chain. If an investigator is driven insane or knocked unconscious whilst on expedition, they are Lost in Time and Space.


These boards are the same. Pick the one whose artistic style you prefer.

Madness board


16 Antarctica - Back 

Preparation Encounters

9 Ma's 8 Science Building 7 Historical Society 5 Hibb's 4 Docks 3 Bank

Expedition Token

You will need a maximum of six of these tokens.

Expedition Token 

Quick Print Files

These rules and encounters are marginally different from those printed, but not especially so.

At the Mountains of Madness Rules and Encounter Index

Credits: This expansion was written by chp mmttn and later updated by Raymond Darby. It has proven so popular that it has even by translated into French

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