Converting Between Call of Cthulhu and Colonial Gothic - Fan conversion guidelines

Oct 6, 2026

Fan conversion guide linking Colonial Gothic and Call of Cthulhu, explaining how the shadow of Lovecraftian mythos carries into colonial-era horror and conspiracy play. Provides recommended sources for Call of Cthulhu games using Colonial Gothic materials, plus step-by-step guidance for adjusting core attributes and resolution mechanics. Includes formulas to translate stats in both directions, along with advice on handling skills, spells, and Traits where systems differ.

LanguageEnglish

CategoryLiterature

FormatPDF

Pages3

Reading Time5 min

AccessFree to download

Converting Colonial Gothic to Call of Cthulhu

Recommended Call of Cthulhu resources

Attribute conversion formulas

Skills, spells, and Traits guidance

Converting Call of Cthulhu to Colonial Gothic

Mythos coverage and licensing note

Reverse attribute conversion formulas

Resolution and vitality calculations

Converting Between Call of Cthulhu and Colonial Gothic Graeme Davis, 3/31/2016 Author’s Note: The following is a fan work and is not intended to challenge any copyrights held by Chaosium, Inc., Rogue Games, or anyone else. Colonial Gothic, Rogue Games’ tabletop RPG of horror and conspiracy at the dawn of American history, owes a great debt to the work of H. P. Lovecraft. The shadow of the Colonial period looms over much of Lovecraft's writing, reflected in his descriptions ofInnsmouth and Arkham and taking a more active role in stories like The Case of Charles Dexter Ward and The Dreams in the Witch-House. With the 2015 release of Colonial Gothic: Lovecraft, players can experience black-powder fantasy adventures against many of the horrors ofthe Cthulhu Mythos. At the time of writing, there is no official Colonial-era source material for Call of Cthulhu, but that game remains the gold standard for tabletop roleplaying adventures against the Mythos. It seems to me that fans of both games can benefit from a rough-and-ready set of calculations for converting stats between the two systems, so here they are. Whether you are adapting Colonial Gothic source material for your Call of Cthulhu game or converting game stats from Call of Cthulhu ’s extensive coverage of monsters, magic, and alien technology for your Colonial Gothic game, I hope you will find these guidelines useful. For those who want to dig deeper into the stats, the AnyDice converter ([www.anydice.com](www.anydice.com)) provides a useful tool for examining probabilities by converting the results of any dice roll into percentages. To see the probabilities for a 2d12 roll, enter output 2d12 in the top window and click the Calculate button immediately beneath. Colonial Gothic to Call of Cthulhu Using this system, the Call of Cthulhu Keeper can turn many of Colonial Gothic's adventures and sourcebooks into resources for an 18th-century Call of Cthulhu campaign, or just for a timetraveling side-track from one of Chaosium's established timelines. The following titles are of particular interest to Call of Cthulhu fans: 􀁸 Second Edition Rulebook: contains general historical and setting information, equipment, prices, common character types, etc; 􀁸 Gazetteer: describes each of the Thirteen Colonies up to 1776, with notes on local mysteries and other items of interest; 􀁸 Boston Besieged: includes a detailed sourcebook on Boston during the siege of 1775- 1776; 􀁸 The Philadelphia Affair: describes the city at the time of the Second Continental Congress and the drafting of the Declaration of Independence; 􀁸 Player Companion: includes detailed templates which are easily adapted to create period Investigator types for Call of Cthulhu; 􀁸 The Bestiary: presents a range of non-Mythos adversaries for rounding out Colonial-era adventures; 􀁸 Many other sourcebooks and adventures are available in print, PDF, ePub, and Kindle formats. STR = Might * 1.67 CON = Vigor * 2.27 SIZ: generate from scratch, referring to similar characters/creatures in the Call of Cthulhu rules. INT = Reason * 1.75 POW: generate from scratch, referring to similar characters/creatures in the Call of Cthulhu rules. DEX = Nimble * 2.17 Skills and spells are hard to convert directly because of differences in the two game systems. However, with a little imagination an experienced Keeper should have no difficulty in coming up with numbers that work, based on the attribute scores, the overall concept and the relevant Colonial Gothic skill, spell, and Trait descriptions. Call of Cthulhu to Colonial Gothic A Colonial Gothic GM can use this system to help convert additional Mythos horrors from Call of Cthulhu sources: the copyright status of the Cthulhu Mythos is complex, and limited the range of creatures that could be covered in the Colonial Gothic sourcebook. Might = STR * 0.6 Nimble = DEX * 0.46 Vigor = CON * 0.44 Reason = INT * 0.57 Resolution: generate from scratch,

FAQs

What is the document’s purpose for Colonial Gothic and Call of Cthulhu?

It offers fan-made conversion calculations to help translate character statistics between the two tabletop RPG systems and use source material across settings.

How do you convert core attributes when going from Colonial Gothic to Call of Cthulhu?

Use the provided multipliers (e.g., STR = Might * 1.67, CON = Vigor * 2.27, INT = Reason * 1.75, POW = Reason * 1.75, DEX = Nimble * 2.17) and generate remaining values from related Call of Cthulhu rules.

How are Vitality and Resolution handled when converting from Call of Cthulhu to Colonial Gothic?

Vitality is calculated as (Might + Vigor) * 2.5, rounded down, while Resolution is generated from scratch based on Reason and POW * 0.5. Skills, spells, and Traits are adapted from the Call of Cthulhu descriptions and supplemented with Colonial Gothic lists.

Oct 6, 2026

Upload by mieayamfan