Grand Campaign – AtB Rules

Spoiler warning – this post contains scenario/resolution spoilers.

My group of fellow investigators and I love to play Grand Campaign style, where we link all of the campaigns to each other, and do them in order.  Typically, this means Core, Dunwich Legacy then what is currently released of Path to Carcosa.  We also sprinkle in the occasional side mission.  Furthermore, we make it a sort of Iron-man mode where we repeat the campaigns on higher difficulties until we all die.  We have little issue with the rules as written, but the sheer amount of trauma thrown at you in the Core scenario resolutions can have very strong results on the campaign as a whole.  In addition, you can accumulate quite a lot of experience points from only 3 scenarios, quickly making further experience gains much less enticing.  The following are some tweaks that I feel make running a Grand Campaign a slightly more balanced affair.  As with all Arkham Horror rules, feel free to change them as you desire.  Note: As more expansions and scenarios are released, I will update these suggestions.


You must start on Standard difficulty or harder.  Easy is just too easy, especially once you move into the Dunwich Legacy campaign and have some upgrades in your deck(s).

At the end of the very last scenario in the Grand Campaign (last one in Carcosa for the order above), the difficulty must increase by at least one level.  Side missions may not be repeated until one complete run through of all campaign scenarios has been completed, but still remain optional with their normal cost (3 xp/investigator).

Once per Core, Dunwich or Carcosa campaign, investigators may spend 10 exp to remove 1 mental or physical trauma.  The 10 exp must be spent all at once.  This is the only way investigators may heal any traumas obtained.  It still counts as the previous cycle until the next cycle starts.  For example, it is still considered during the Core campaign after The Devourer Below up until the moment the first scenario of the next campaign begins (probably Dunwich).  Side missions do not count as a separate campaign.

As with the standard rules, any time a weakness card is added to an investigator, it remains part of their deck until that investigator is killed or retired.

Chaos tokens added to the cup by scenarios and resolutions remain part of the cup throughout the entire Grand Campaign.  If repeating after the completion of all scenarios on a higher difficulty, reset the cup to it’s default configuration in the campaign rules.

If the investigators choose to increase the difficulty before a complete run of all scenarios, do not remove additions to the cup from scenarios.
Example: Ron and Lisa start out with the Core scenarios and before they start the Dunwich Legacy campaign, wish to increase the difficulty from Standard to Hard.  Remove the default Standard tokens, replace them with the Hard configuration, but the Elder Thing token added in The Devourer Below remains in the cup.

If an Elder Thing token is in the cup, but there is no modifier for an Elder Thing on the current scenario card, treat it as a -3 for Standard, -5 for Hard/Expert.

Notes in the Campaign Log reset each time the investigators complete the final scenario in their collection.  In addition, all story assets return to the collection at the end of completing the final scenario in the collection, including non-basic, non-signature weaknesses.

Between scenarios, investigators may “retire” and pick a new investigator, starting with 0 exp and using the standard deck-building rules for that character.  Investigators that are killed or retire may not return, and the players lose if one cannot be replaced by an available investigator.  The number of players may not decrease.

If you have to gain a basic weakness of any kind, but run out of basic weakness cards in the collection, suffer a mental trauma instead.

Core Scenarios:

The Gathering

Remove the bonus experience (+2) gained from all resolutions.  Lead investigator still gains +1 exp in R2.

Any investigator may add the Lita Chantler card to their deck instead of just the Lead.

The Devourer Below

Resolution 1 – Each investigator suffers 1 mental trauma, but only gains 2 bonus experience.

Resolution 2 – Each investigator suffers 1 mental and physical trauma, but only gains 4 extra experience.

Resolution 3 – Each investigator suffers 1 mental and physical trauma.  In the event there are no more Madness weaknesses in the collection, take a random basic weakness instead.  Record in the campaign log that investigators are horrible people and should be ashamed.

These changes are made with the idea that you shouldn’t leave the Core scenarios with a mass of experience, but also without a massive amount of traumas (being defeated not withstanding).  This increases the value of Victory X locations, incentivizing complete investigations.  Also, it creates a situation where investigators may want to save up the initial exp gains to heal one of those traumas moving forward, meaning less exp to devote to upgrades.  I feel it discourages playing characters like Roland when you’re looking at 2-3 mental trauma even if you succeed without being defeated.


So far, we haven’t come across anything major worth changing in the Dunwich Legacy and Path to Carcosa cycles, but future play-throughs may change this point of view.  Once Return to the Night of the Zealot launches, it is likely we will change the Grand Campaign suggested order, and perhaps only go through the Core scenarios once just to serve as an introduction.  However, we will need the full campaign and scenario details before deciding.  If you have any suggestions, questions or you just want to share some of your house rules when running a Grand Campaign, feel free to comment them below!  Thanks for reading and good luck around the board.

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