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d20 Call of Cthulhu Gamemasters Pack

This essential supplement for the d20 edition of Call of Cthulhu contains the most important tables & rules synopses to make d20 Cthulhu game sessions easier & more enjoyable for the GM. Includes the 32 page adventure The Lost temple of Yig, character sheets, NPC records, Monster Sheets, conversion notes between d20 Call of Cthulhu and the Classic Basic Roleplaying Call of Cthulhu, and more.

The D20 Cthulhu GM Screen is fully compatible with the d20 version of CALL OF CTHULHU published by Wizards of the Coast, produced under license from Chaosium Inc.


Sturdy three-fold screen will stand up to years of use.

Includes a complete 32 page d20 Call of Cthulhu adventure by Aaron Rosenberg.

Based upon the writings of H.P. Lovecraft and his circle of Cthulhu Mythos writers.

Fully compatible with the d20 Call of Cthulhu published by Wizards of the Coast produced under license from Chaosium Inc.

Includes official guidelines for converting Chaosiums Classic Call of Cthulhu adventures and sourcebooks to d20 Call of Cthulhu - so d20 GMs can use previously printed adventures and sourcebooks for their d20 Cthulhu campaigns.

The only d20 GM screen published for Call of Cthulhu d20.

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First Post
d20 Call of Cthulhu Gamemaster's Pack
By Aaron Rosenberg and Dustin Wright
Chaosium Inc.
#8801 ISBN 1-56822-166-2 $19.95

This is not a play test review. I will be rating items on a scale of 1 to 10. 1 being the worst I ever seen, and 10 being that I believe that no product will ever match this one in quality.

From the back: This package holds a wealth of resources for the new or experienced d20 Call of Cthulhu gamemaster. Within it's musty pages you will find:
A Full-color Gamemaster's Screen: All the vital charts and tables for running a d20 Call of Cthulhu game lurk behind a full color painting of Cthulhu itself.
4 Index bookmarks: Hold your spot in four different areas of the d20 rulebook, and quickly look up relevant rules.
Dire Documents: A folio of fiendish forms, containing 16 forms for asylum admittance records, blank police reports, dental records, and more!
Complete Conversion System: Quickly and easily convert gods, monsters and investigators from classic Chaosium Call of Cthulhu products to the new d20 rules set!
Errata: Official corrections to the d20 Call of Cthulhu rules. Including full statistics for Y'Golonac!
The Lost Temple of Yig: This thrilling adventure takes the investigators deep into the heart of the Amazon jungle. Dual stats are provided to use this scenario with either version of Call of Cthulhu!
And much more!

It boasts on the front:
OFFICIAL! Includes material omitted from the rulesbook.
The Vanguard Club
Forms and Letterheads
Official Errata and Corrections
Cardstock Gamemaster Screen
"The Lost Temple of Yig" adventure
Indexed Rulesbook Bookmarks
Corrected Investigator Sheet
Conversion Rules for using Chaosium Supplements

The cover is just a picture of the Wizards of the Coast cover for the d20 Call of Cthulhu Roleplaying Game. I guess this is done so you know this is d20 instead of BRP (or known as "Classic Cthulhu"). I would of liked some new art. On the back of the front cover piece is ads for upcoming products from Chaosium for CoC. Three "Classic" products: 1920s Investigator's Companion, H. P. Lovecraft's Dreamlands, and Keeper's Companion. And three dual-stat: Pulp Cthulhu, Return to Dunwich, and Arkham Unveiled.

First, I will discuss the Gamemaster's Screen. The art facing the investigators is a color painting of Cthulhu by John T. Snyder in the "Classic Cthulhu" Chaosium style. 'Cthulhu at R'lyeh' is from the current BRP hardback version. So nothing new again. It conveys the feel of CoC very well. The interior art has two pictures of some sort of monsters that I could not truly name but they look like a skeleton and a ghost. In the middle is the picture of The Elder Sign. Also shows some symbols: The Eye of Light And Darkness, The Elder Sign, Sign of the Dark Mother, The Sign of Eibon, The Yellow Sign, and The Pnakotic Pentagon.
The GM Screen has the following 16 tables:
d20 CoC Quick Index lists the pages for Combat, Environmental Hazards, Feat Descriptions, Insanity, Investigative Gear Price Lists, Magic, Psychic Feat Descriptions, and Skill Descriptions.
Fleeing explains how Double Move and Run work.
DC Examples shows DC Difficulty from Very Easy (DC 0) to Heroic (DC 30)
Action Types tell you what a character can do during a round.
Object Hardnesses detail objects hardness, hit points, and break DC from Rope to an Iron door.
Abilities show what your modifier would be for your ability scores such as Strength and so on from 1 to 21.
Combat Spot Rules shows rules and their page for: Attacks; Attack Options; Death, Dying, and Healing; Initiative; Massive Damage; Movement; and Saving Throws.
Cover details Degree of Cover, Bonus to AC, and Bonus to Reflex Save from One-quarter to Total.
Detecting Invisible Creatures lists the Condition and Listen DC from In combat or speaking to Obstacle: stone wall.
Attack Roll Modifiers has the Circumstance for Melee or Ranged from Attacker flanking defender to Defender helpless.
Spot Rules for Spellcasting has Casting Time, Range, and Spell Saving Throw with page numbers.
Spot Rules for Sanity shows Threshold and Cause. And also shows what Maximum Sanity is.
Sanity Loss Examples example Unnerving or Horrifying Situation and its Sanity Loss.
Temporary Insanity is a small table:
d10 Insanity Type Duration
1-7 Short 1d10+4 rounds
8-10 Long d10x10 hours
Short Term Temporary Insanity Effects shows a chart of a d% roll and the Effect on the Character from fainting to catatonic.
Long Term Temporary Insanity Effects is from a character performs compulsive rituals to lose ability to communicate via speech or writing.

The GM Screen has black print on a dark bluish-gray background. Very hard to read. It only has three panels. It is flimsy. For a starting GM new to CoC and d20, this shows the basics. So for a newbie this item gets a rating of 5. An experienced GM is better off making their own.
d20 Call of Cthulhu Gamemaster Screen gets a rating of 3.

Second, the Bookmarks. You get four of them that list the page numbers for the following: Characters & Equipment, Combat & Other Dangers, Creatures, Cults and Other Horrors, and Insanity & Magic. Dark brown print on a light tan field. Easy to read. Made of a thick paper. Not glossy or as thick as the GM Screen. I could take em or leave em. I rather have the money spent made on these to better the rest of the Pack. But it is a nice touch. They were last used this way in the Fifth edition Keeper's Kit (#5110, 1992). I give the Bookmarks a 6.

Third, Gamemaster's Forms pack. You get 4 pages folded into 16 (8.5 in. x 11 in.) forms printed on back of each other. They are of the following: Arkham Sanitarium Inpatient Admission Form, Commonwealth of Massachusetts Certificate of Insanity, Arkham Sanitarium letterhead, Arkham Sanitarium Dr. Eric Hardstrom, Arkham Sanitarium Patient Record, Arkham Sanitarium Patient Transfer Form, Arkham Sanitarium Patient Psychological Profile, Arkham Sanitarium Invoice of Services, Arkham Sanitarium Visitor Registration Form, Miskatonic University letterhead, Police Department Arkham Massachusetts, Arkham Massachusetts Court form, G. R. Feldman D.D.S. Dental Records, Commonwealth of Massachusetts Certificate of Death, Office of the Mayor Award for Meritorious Service, and Keeper's Choice Award For The Superlative Demise of.
I didn't see anywhere if they give permission to copy these Forms, the handouts in the adventure, or the Record Sheets. I like these forms. They add good flavor. You could look online for more official looking documents for your own hometown or state. The forms pack will be familiar to owners of 'Dire Documents' (#5112, 1993). I give the Gamemaster's Forms an 8.

The next 5 parts are in the Adventure and Resources Book. It is 56 pages long (Only 49 are of use) and in black and white. The front lists credits. Second page is an art piece of H. P. Lovecraft by Paul Carrick. Nicely done. The second page lists copyrights and so forth. Also informs you that this Chaosium Inc. product contains no Open Game Content. Third page is the Table of Contents: Introduction by Ben Monroe, The Lost Temple of Yig, The Vanguard Club, d20 Call of Cthulhu Errata, Conversion System, and Record Sheets.

Fourth up is the adventure, The Lost Temple of Yig (listed pages 1-30). It is dual-stat. I'm not going to give any spoilers. It starts in Arkham in the year of 1933. So this way you will have a glimpse of their future product, Pulp Cthulhu. Think more along the lines of Robert E. Howard Mythos instead of H. P. Lovecraft. The style of play is Doc Savage, The Shadow, and Indiana Jones. They assume the investigators start out as members of The Vanguard Club, but gives ideas why they would be together if you don't start out this way.
Most of the adventure is written for "Classic CoC" than for d20. I don't own any BRP products and only have played "Classic CoC" a few times. I thought this product was to be a focus more on d20 with dual-stats to please the BRP crowd. Not the case at all. Many errors for the stats of NPCs and creatures. Or not showing stats that would be helpful. No CRs or Encounter Levels are listed but that's ok since this is CoC, not D&D. But it would have been nice. They show three of the handouts twice. Two of them labeled wrong both places. All we need is the one toward the back since it is nicely done on one page.
I don't think Chaosium has read a D&D or a d20 adventure. The use of the Jump skill in which I thought Tumble would be more appropriate. And not having DCs listed for some skill checks.
The adventure itself is ok. But for someone new this would be a challenge to run and for everyone to have fun. It will take a lot of work to run this adventure properly. I would have liked some floor plans and such. Just to make the fight scenes easier to run. Remember this adventure is set in the pulp genre. So fighting instead of running is encouraged. It does have a lot of pictures that you can show the players. The major NPCs have a picture and decent background. I want from a purchased adventure module more help on how to run it. I would become a better GM if I were given more guidance. Reading through this didn't inspire me to quick call my friends to play CoC. When I first started reading The Lost Temple of Yig, I was looking forward to running it. But once I got to where the PCs have their first real encounter, it was downhill from there. It has good premise, but then seemed rushed. For an experienced GM, I give The Lost Temple of Yig a rating of a 4. For a newbie a 3. For Chaosium's first d20 adventure it falls flat.

Fifth, The Vanguard Club (listed pages 31-36). This organization was created by a group of daredevils, scientists, and adventurers. Its sole purpose is to explore the unknown and thus expand Man's knowledge of the world and his place in it. As a secondary purpose, the Club investigates the supernatural and either debunks hoaxes or reports back about real phenomena. It is best summed up by its motto: Semper Primus ad Limes. (Always first to the Frontier.) This small chapter details the Purpose, Organization, History, and The Arkham Club to a small extent. The forthcoming Pulp Cthulhu will contain even more information on the Club and other similar organizations. This chapter is all fluff and no crunch. It is a good read with nice flavor. Hopefully we will see stats in Pulp CoC. I give The Vanguard Club a rating of a 7.

Sixth, d20 Call of Cthulhu Errata (listed pages 37-42). This is where some errors have been caught for the Wizards of the Coast CoC hardcover. Please note that no credit was given to the forum contributors (myself included) whose posts were often used verbatim or nearly so. You can look here on Monte Cook's boards for more information at
What can I say? Only a couple items did Chaosium do the work themselves. I was hoping the Chaosium and WotC would of worked together to have more of an official erratum. They also printed the stats for Y'Golonac. WoTC had the stats for it on its CoC web page a couple months before hand. They also print what Intuit Direction, Darkvision, Elementals and its advancement, and Improved Grab are. I give d20 Call of Cthulhu Errata a rating of a 2 for being so lazy.

Seventh, Conversion System (listed pages 43-46). It is an expansion of the conversion rules given in the WotC d20 CoC rulebook. This is what should have been in the core book. This chapter shows how to convert BRP to d20. As it states, use these rough notes as an aid. I was hoping for more. I give the Conversion System a 6.

Eighth and last, Record Sheets (pages 47-51). They give us two d20 Call of Cthulhu minor record sheets, a two-page CoC Horror Role-Playing Player's character sheet, and a d20 CoC Monster Master (with 3 Minions) record sheet. All within the whole book they list Ranged weapons as missile. It is the same with the Record sheets. The character sheet is a better improvement than the one in the core book but still is inadequate. The weapons section is missing a spot for Rate of Fire. I don't have any thoughts on the minor and monster sheets. I give Record Sheets a 7.5

The cost of the d20 Call of Cthulhu Gamemaster's Pack is typical for its use. If you aren't a die-hard CoC fan & GM, I suggest that you pass on this product. My final rating is a 4.75 or for ENWorld a 2 because I just can't round up to Average in this case. The writing is good but the rule mishaps, editing, and the need to help the GM out more for the adventure just brings it down.
This product was first to be a GM Screen I believe and come out when the core book did in March. It got pushed back and back. Then it was updated to the Gamemaster's Pack to be out in June. Well finally I have it in my hands in August. Was it worth the wait? Chaosium says they don't want to rush a product if it isn't of quality. Then I don't want to know how many years it will take for them to do so. This being my first purchase from them, I was disappointed. Will it stop me from buying further CoC products? No. I can tell they have a passion for Call of Cthulhu. I will just be more selective in my buying habits. I hope they will have more freelancers support d20 CoC.

Peace and smiles :)



Hey, nice thorough review. I am a big fan of CoC D20 and this really helped me in deciding if I wanted the GM's screen (yes I do). I think you may have been a bit harsh in some of your criticisms though as in the sessions of CoC D20 I have run we rarely looked into the more complex rules that exist in D20. I prefer a screen that gives me page numbers so if I don't exactly have a rule memorized I can look on the screen and get the exact page I need. This made the Scarred Lands screen an awesome addition to the game. I use it over my FR screen which I use more for the weapons listing. Maybe a better title would have been GM's reference screen?

The adventure, though I haven't read it, sounds like it may have been written for BuRP rather than D20, but again, it is simple to convert and use average difficulties etc. I have never had a hard time ad hoccing what the DC should be for a conversion and I have even run a few 2E adventures as 3E stuff with little to no conversion.

Anyway, thanks for the review, it was very thorough and helpful for me and my group, even though you gave it a 2. Sometimes people need to look at reviews as what applies to that person or group doing the review and realize it is not necessarily what applies to themselves. =)



The first supplement for D20 Cthulhu is here: The GM's Pack.

Here's what you get:

A 3 panel GM Screen

4 Bookmarks which also are printed with page references to various areas in the D20 CoC rulebook

A fairly meaty 50 page book filled with a variety of useful things for your CoC game.

A finally a Booklet of various forms and sheets.

all for $19.95 US.

The GM Screen

The GM screen is a 3 panel affair that has the cover picture from the 5.5/6 Edition of the CoC BRP system Core book on the side facing the players (nice art by the way), and on the GM's side has many of the most useful tables for the D20 version of CoC, as well as a mini-index. Tables include: DC examples (with generic difficulty levels, i.e. easy, avergae, tough, etc. No specific tasks are referred to), Object Hardness, the Ability Score modifier table, Fleeing (how appropriate!), Action Types, Combat "Spot" Rules, Cover, Attack roll Modifiers, "Spot" Rules for Spellcasting, Detecting Invisible creatures, "Spot" rules for Insanity, Short & Long term Insanity effects, Sanity Loss examples, Temporary Insanity, and finally a few of the symbols/glyphs of the Mythos. It sounds like alot, but the screen is actually pretty small compared to most screens, and is not over-crammed. It makes good use of the space, but due to the simpler nature of the CoC rules (regardless of version), you probably won't need much more in the way of tables for in-game use. Some of you may be wondering what "Spot" rules are. "Spot Rules" are a term used for quite some time by Chaosium to put a small, but sufficient amount of rules mechanics to run the game in one "spot" or that can be looked up "on the spot". Essentially it's a few paragraphs or a page of needed rules and mechanics to run one aspect of the game, be it firearms, spellcasting, etc. If you are familiar with Angramainyu's 3E's reference sheets, then that should give a general idea of what "Spot rules" are like. The Screen itself is a bit flimsy and not of heavy stock, but I don't find it any worse than the original 3E DM screen from that standpoint. Overall a solid, utilitarian GM screen.

The Bookmarks

The bookmarks (4 of them) are just that: Bookmarks. However, each is printed with a mini-index of sorts. One has a Character & Euipment Index. Another is for Creatures,Cults, and other horrors. A third is for Combat and other Dangers (Such as fire, falling, etc), and the last is (at least in my GM pack) a repeat of the 1st (Characters and Equipment). Nothing groundbreaking here, but they should prove useful at times.

The Booklet

Ahh, here is the meat of the CoC GM pack! This 50 page booklet is filled with a variety of things.

First off is a rather "pulpish" CoC adventure entitled "the Lost Temple of Yig". I won't go into details here, other than to say the PC's will be going to Brazil to explore a lost Temple (imagine that!), should prt well to any era, and that it's 28 pages in length. Overall a decent work, but nothing special. BRP stats are included at the back for the major NPC's and there is a new (D20)spell too.

Next up in the booklet is an "Adventurers Guild" the PC's could become involved with named "The Vanguard Club". The organization is a group of world-spanning explorers whose motto is "Semper Primus ad Limes", which translates to "Always First to the Frontier". The Club's History, Organization, Internal Politics, etc are given a brief (5 page) but enough to work with, overview. Included is a small writeup on the Arkham Club. The Club, like the "Lost temple" has a very (intended) Pulp-ish 1930's feel. However, with a minimal amount of work the GM could bring it into a modern-day era game, if desired.

After that is the official D20 CoC Eratta; about 3 pages worth and a "new" monster. I somehow find it hard to believe this ALL of the Eratta in the D20 CoC book, though by no means am I certain of the matter.

Then we find an expanded D20 to BRP (or vice versa) Conversion section. It's only 3 pages, but is more detailed that the material in the D20 CoC core book for converting established CoC products to D20.

Lastly we have some Record Sheets. These include a new PC Record Sheet (which I prefer over the WOTC version, as it's "cleaner" and easier on the eyes), a Minor Character sheet (for NPC's), and a Monster Master. The Monster Master has a main area for whatever "main baddie" you are using, plus smaller sections for up to 3 of it's minions. Again, nothing groundbreaking, but solid, utilitarian, and useful.

The Forms and Sheets

Ok, I have to admit, I'm a sucker for this type of stuff. This booklet includes various "props". Included are "Official" Arkham Sanitarium Admission Forms, a Commonwealth of Massachusetts Certificate of Insanity, Arkham Sanitarium Letterhead (both generic and for Dr. Eric Hardstrom, the Chief of Staff), a Arkham Sanitarium Patient record, a Arkham Sanitarium Patient transfer form, a Arkham Sanitarium Patient Psychological Profile form, Arkham Sanitarium Service/Equipment Invoice, a Arkham Sanitarium Visitor Registration Form, Miskatonic University Letterhead, Arkham, Mass Police Department forms (one for criminals, another for crimes/cases), a Dental record, a Death Certificate, an Award for Meritorious Service from the (Generic town) Mayor, and finally a "Keeper's (GM) Choice Award for the Superlative Demise of (insert deceased investigator's name here) Award", which obviously is a gag, but fun nonetheless. Of course all of the sheets are blank and meant to be filled out by the GM as "clues' or whatnot in-game. Way cool stuff, and they certainly help to evoke the CoC mood


As I said about some of the individual items, there is nothing groundbreaking here. Nor is it a typical D&D/D20 release full of "crunch" like feats, spells, etc. This accessory lives up to it's name: it's simply a set of useful items for the CoC GM. The scenario is decent and should keep PC's busy for a few hours, there arequite a few ideas/seeds present for a GM to mine in the Vanguard Club section, the Eratta is obviously helpful, the somewhat expanded Conversion section is more than welcome so that the D20 fan may buy and use with relative ease any of the plethora of excellent existing CoC material from Chaosium, and the various forms will help to add atmosphere to the game. Considering that most DM screens run $10 to $12, and a 28-32 page D20 adventure runs from $8 to $10, I feel this is $20 well spent for any D20 CoC GM.

JeffB [:)]

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