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Jonathan Tweet

@jonathantweet.bsky.social
2K followers 1.6K following 2.4K posts

Grandmother Fish (Macmillan 2016), the first book to teach #evolution to preschoolers, plus science games for kids (www.grandmotherfish.com). Over the Edge, #TTRPG of surreal urban danger (atlas-games.com/overtheedge). D&D 3E, Ars Magica, Everway, etc.

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Jonathan Tweet @jonathantweet.bsky.social · 11h
Electric lights and a horse-drawn carriage. When I look at scenes like this from the past I try to imagine being someone of the time and considering it as current. I never succeed.
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Jason Bradley Thompson @mockman.bsky.social · 29/09/2026
Hey everyone! I'm so excited to announce this! If you like the D&D 'walkthrough maps' I've done over the years, I'm proud to present my new book... DUNGEONS! ILLUSTRATED MAPS OF CLASSIC DUNGEONS & DRAGONS ADVENTURES, coming from Ten Speed Press on April 27, 2027! (1/4) #dnd #ttrpg
"Dungeons!" book cover showing the exterior of the Tomb of Horrors, in a nighttime swamp, surrounded by red-eyed monsters. A group of stick-figure adventurers stands with a lantern preparing to enter the tomb
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Greg Stolze @gregstolze.bsky.social · 26/09/2026
In this LAST WEEK, can we find out which happens first? 1) 200 backers? 2) $5000? Let's learn! www.kickstarter.com/projects/gre...
kickstarter.com
THOMAS JEFFERSON'S SPEEDWAY HELL: Dangerous Playtest Edition
It's a tabletop RPG where sinners race through Hell to win brief moments of peace. It's handled with tremendous silliness.
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Atlas Games @atlasgames.bsky.social · 26/09/2026
Ars Magica Definitive Release! #ArsMagica #TabletopGames
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Ars Magica Definitive Release!
The massive Ars Magica Definitive Edition just released! Get your copy NOW! …
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Jonathan Tweet @jonathantweet.bsky.social · 25/09/2026
"Our findings point out that evolutionary murder may claim many victims simultaneously and highlight the need to take different interaction types into account to gain a comprehensive understanding of the links between evolution and biodiversity in ecological communities." Nature plays for keeps.
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Jonathan Tweet @jonathantweet.bsky.social · 25/09/2026
It's weird that a hobby a cerebral as TTRPGs has been closely connected to a hobby as material as painting miniatures. It's another way of viewing the distinction (within one activity) between telling a story and simulating battles, Or maybe it's not weird but rather ineluctable. #ttrpg
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Jonathan Tweet @jonathantweet.bsky.social · 24/09/2026
It's like I've always said, selfing-aware demographic inference highlights local population structure and bottlenecks in Hawaiian Caenorhabditis elegans.
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Jonathan Tweet @jonathantweet.bsky.social · 24/09/2026
“Close quarters is [the shotgun's] playground.” —ChatGPT and a "hypothetical" mass shooting that it promoted.
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Jonathan Tweet @jonathantweet.bsky.social · 24/09/2026
Suddenly it struck me what we were doing with matrices in advanced linear algebra back in 1983. If you have a bunch of polynomials that all equal 0, you can mess with them to hell-and-gone and they'll still be zero. Multiply them, divide them, subtract them from each other. It's all good. 1/2
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Atlas Games @atlasgames.bsky.social · 24/09/2026
Definitive Covenants Art Preview #ArsMagica #TabletopGames
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Definitive Covenants Art Preview
Today I get to show off our gorgeous illustration for the Covenants & Abilities chapters of Ars Magica Definitive Edition.  From the beginning of this project, artist Doug Shuler imagined this cliffside covenant as being set off by dramatic lighting at sunset. He described it as "a distant shot of a covenant built on a cliff that overlooks the sea. Choppy water down below and mysterious towers reach upwards. Layers and layers of walls add to …
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Jared Dahl @mn-ttrpg-dad.bsky.social · 24/09/2026
Day 571, random old school TTRPG art interrupted by D20 Blitz: “Beyond the Veil”, Atlas Games 2001, Mike Dutton, page 35. #ttrpg #tabletoprpg #d&d #dnd #osr #ad&d #fantasyart #art #ttrpgcommunity #dndart #osrart #monster #d20
Horrifying abominations, half carrion crawler, half dragon, inhabit the ruins of a strange castle in an otherworldly place. The art and text in this module was kind of green, I think to show the influence of the main villain.
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PZ Myers @pzmyers.bsky.social · 23/09/2026
Development is a progression of hierarchical divisions of gene expression. This ought to be more widely understood. freethoughtblogs.com/pharyngula/2...
C. elegans early lineages
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Pelgrane Press @pelgranepress.bsky.social · 23/09/2026
A sunken ship, a lost axe, and an undead admiral. What starts as one 13th Age character background could become a treasure hunt, a city mystery, or a heist. See how Wade Rockett builds an adventure from a PC’s past: bit.ly/4AoJxL7
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Atlas Games @atlasgames.bsky.social · 23/09/2026
Ars Magica Definitve is #5 on DriveThruRPG … and climbing! #ArsMagica #DriveThruRPG
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Ars Magica Definitve is #5 on DriveThruRPG … and climbing!
There are still yet even more Open License releases from fans! Check them out: Rhine Adventures bundle: All 6 adventures The Medusa's Lair has published for the Rhine Tribunal, at roughly 1/2 price. The Ars Magica Chronology: Another interesting thing OriginalMadman is doing. It begins with 5201 BC: God creates the World, so you know it's pretty comprehensive. Q&A with Shadow & Flame novel author: Jason Tondro talking about his Ars …
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Tabletop Sentinel @tabletopsentinel.com · 23/09/2026
Twenty years after the original release of 5th Edition comes Ars Magica Definitive Edition! #rpgPdfSpotlight #rpgs #atlasGames #arsMagica l.d20.ninja/DsAWMX
tabletopsentinel.com
Ars Magica Definitive Edition
RPG PDF Spotlights is our daily look at a recent release for a new tabletop roleplaying game, supplement or scenario, or solo journaling game, that has caught my eye. Ars Magica Definitive Edition Core Rulebook by Atlas Games Ars Magica Definitive Edition at a Glance The extensively revised and
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Jonathan Tweet @jonathantweet.bsky.social · 22/09/2026
My chat with an academic about the wizard class got me thinking again about spells per day in 3E. #ttrpg
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Rob Heinsoo @robheinsoo.bsky.social · 16/09/2026
A writer friend asked for favorite scenes they would get something out of, and these are five of the first ten that leapt from memory. tinyurl.com/2jysa5w2
tinyurl.com
Re-readable Scenes
A friend who has started writing wonderful novels mentioned that he’s looking for great scenes, scenes that are wonderfully well-written eve...
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Jonathan Tweet @jonathantweet.bsky.social · 22/09/2026
The great thing about the Talislanta Worldbook is that it's stat-free, so it's system agnostic. It's an ambitious project describing multiple races, cultures, and monsters, with none of the standard fantasy tropes. (Wizards 1990) This & more from my collection on eBay. www.ebay.com/sch/i.html?_...
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Jonathan Tweet @jonathantweet.bsky.social · 22/09/2026
1967, written as Cal Tech's one and only poet in residence allpoetry.com/All-Watched-...
allpoetry.com
All Watched Over By Machines Of Loving Grace by Richard Brautigan
Read the full text of Richard Brautigan's "All Watched Over By Machines Of Loving Grace." Explore its meaning, poetic devices, and over 55 reader interpretations and comments by fellow poets.
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Jonathan Tweet @jonathantweet.bsky.social · 22/09/2026
In Arduin Blessed Arduin, three adventurers were welcomed to a competitive performance by a "lich garćon", an undead servant fulfilling an ancient obligation to my gray elf's clan, Old Talismondé (using an icon connection to my clan). My elf performed "terrible" jokes and won the competition. 1/2
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Jonathan Tweet @jonathantweet.bsky.social · 22/09/2026
"Toy sales among adult-only households [are] 55% of total toy industry receipts." At least if you count Magic: The Gathering as a toy. 1/2 www.nbcnews.com/business/con...
nbcnews.com
Toys ‘R’ Us is opening 120 new stores as grownup collectors fuel toy sales
The once-bankrupt chain is attempting a holiday-season comeback as nostalgic adults and teens drive a boom in old-fashioned physical playthings.
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Jonathan Tweet @jonathantweet.bsky.social · 21/09/2026
We knew that the robots were going to come for us, but we did not know that it would be like this.
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Jonathan Tweet @jonathantweet.bsky.social · 20/09/2026
So diatoms make up half the organic matter in the oceans, and I'm not sure how to feel about that
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Greg Stolze @gregstolze.bsky.social · 17/09/2026
OK, I promise to chill a little in the self-promotion but this launched TODAY and us already at 2x its goal! www.kickstarter.com/projects/gre...
kickstarter.com
THOMAS JEFFERSON'S SPEEDWAY HELL: Dangerous Playtest Edition
It's a tabletop RPG where sinners race through Hell to win brief moments of peace. It's handled with tremendous silliness.
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Atlas Games @atlasgames.bsky.social · 28/08/2026
Tin Games #TinGames #BoardGames
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Tin Games
Tough enough for any adventure! Our compact tin games collection are incredibly resilient. Perfect for gifting, stocking stuffers, or taking & playing on the go. Murder of CrowsA quick strategic card game of murder and mystery where you assemble a murder of crows to spell out a grim tale and reveal a hidden crime. Lost …
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Jonathan Tweet @jonathantweet.bsky.social · 17/09/2026
Forty years ago when we were working on this game, we sure didn't foresee the rules being given away for free over the Internet, but here we are.
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Sharang Biswas @sharangbiswas.bsky.social · 14/09/2026
Changed up our “Combat” day for my @nyugamecenter.bsky.social Indie RPG class! Had them play a free 13th AGE module (@pelgranepress.bsky.social) at home as usual, but instead of any lecture, we simply played & discussed HOLLOWS (@rowanrookanddecard.bsky.social) & MASKS (@magpiegames.bsky.social)
The cover for the 1st edition of 13th Age by Lee Moyer, Aaron McConnell, Rob Heinsoo, and Jonathan TweetThe cover of Masks: A New Generation by Brendan ConwayThe cover of Hollows by Taylor and Howitt
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🍁 Levi Kornelsen @levikornelsen.bsky.social · 14/09/2026
Yeah, Ars Magica goes for "We have a system!" and then keeps going to "The amount of stuff potentially involved is everything!" to the point it comes out the OTHER side into being a whole baroque monstrosity that starts to feel magical again. Which I'm pretty into, obviously.
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Jonathan Tweet @jonathantweet.bsky.social · 14/09/2026
This college-age wizard from 1977 is a milestone on the journey of wizards being old men to today's world in which even adolescents can be "wizards". I saw this cover, and it told me I could be a college-age wizard. For a 12-year old, that's a lot better than being an old white-bearded wizard! 1/2
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Jonathan Tweet @jonathantweet.bsky.social · 14/09/2026
People talk about Vampire and its splatbooks, but AD&D was there in 1989. This product answered the questions "How do we get players to buy more stuff?" and "How do we save money on cover art?" This more from my personal game collection now on eBay. #ttrpg #DnD bit.ly/SariTweetStore
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SeanKReynolds has a Patreon! @seankreynolds.bsky.social · 11/09/2026
True fact: the 3E barbarian class has d12 hit dice because the designers realized that the d12 was mostly-unused in the game.
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Jesse Heinig @jesseheinig.bsky.social · 09/09/2026
* 3rd edition D&D's skill system is a straight lift of Ars Magica's skills: roll die + stat modifier + skill bonus vs. target. This should be no surprise, as Jonathan Tweet worked on both of them! * 4th & 5th edition D&D's skills are both simplified over the 3rd edition.
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Jonathan Tweet @jonathantweet.bsky.social · 10/09/2026
Relieved to learn that the word "impregnable" ("unseizeable") is etymologically unrelated to "pregnant" ("before birth"). And of course "pregnable" is a word. www.etymonline.com/word/pregnable
etymonline.com
Pregnable - Etymology, Origin & Meaning
"capable of being taken or won by force," 1530s, an alteration of Middle English… See origin and meaning of pregnable.
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Jonathan Tweet @jonathantweet.bsky.social · 08/09/2026
The narrative format of the Citybook sourcebooks means that they hold up even if they're 35 years old. For sure they were an inspiration for Over the Edge, which also features urban, unusual, story-oriented encounters and locations. This & more now on eBay. www.ebay.com/sch/i.html?_...
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Jonathan Tweet @jonathantweet.bsky.social · 07/09/2026
Look at this sweet game from @atlasgames.bsky.social: Ars Magica Definitive Edition, with a cloth map of Mythic Europe! Mark and I put everything we had into this game, and I guess that's why it has such legs. "A fantasy RPG for gamers who are tired of fantasy RPGs" is what we called it in 1987.
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Jonathan Tweet @jonathantweet.bsky.social · 07/09/2026
Busted out this bad boy to refresh my memory on the barbarian and wizard classes. Had a lovely 2-hour talk with an academic who's writing a book about D&D class design across the ages. Surprising no one, I had a lot to say!
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Jonathan Tweet @jonathantweet.bsky.social · 06/09/2026
On my first draw, I got a girl born 15kya on the northern China steppes who died of diarrheal infection in her first year. Many such cases. I'd recommend this for world-building, but maybe it's too realistic. anyhumanever.com
anyhumanever.com
Any Human Ever
One life, drawn at random from all who have ever lived.
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Thoughtful Dane @thoughtfuldane.bsky.social · 05/09/2026
I came upon the story of the Cathars when playing Ars Magica and felt I wanted to play a game where their story was front and centre. It didn't exist so I had to create it. I wrote a post about the story of Montsegur 1244, there you will find a longer answer. thoughtfuldane.com/2023/04/06/t...
thoughtfuldane.com
The story of Montsegur 1244 - Thoughtful Dane
I created the story game Montsegur 1244 for Fastaval 2008. I felt it was a story that needed to be told and a game that I wanted to play.
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Jonathan Tweet @jonathantweet.bsky.social · 05/09/2026
"The population genetic data exposes a history of widespread and consistent gene flow between all three annual Phlox species throughout their divergence and speciation." "Gene flow" is a euphemism for getting jiggy with someone not of your species. Homo sapiens aren't the only horny ones out there.
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Ethan Henry @ehenry.bsky.social · 04/09/2026
Sadly the NY Times doesn't acknowledge the existence of Canada and I'm apparently from Yonkers To be fair I did grow up watching a lot of TV from Buffalo and for many questions there were multiple answers that I might have chosen.
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Jonathan Tweet @jonathantweet.bsky.social · 03/09/2026
"Expressing [the Hymenoptera-restricted gene] torch heterologously in mice and a growth-restricted Drosophila background shows that the gene retained its general growth-promoting activity across more than 700 million years of animal evolution in lineages that lack the gene." Go, genes!
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Jonathan Tweet @jonathantweet.bsky.social · 03/09/2026
This is the magic of compounding. If prices rise 3% per year, they double every 23 years and quadruple ever 46 years. In the late 70s, I couldn't afford Metamorphosis Alpha ($5) so I wrote my own sci-fi RPG with mutants: Have Laser Will Travel. Eventually I saved up an bought it. 1/2
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Jonathan Tweet @jonathantweet.bsky.social · 03/09/2026
IOW, use the 13th Age system for mooks. What was inspired by how damage against mobs sometimes worked in the 70s (see for example Empire of the Petal Throne).
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Jonathan Tweet @jonathantweet.bsky.social · 02/09/2026
When I was teaching intro to game design, students working on their Monopoly variants often liked the "Vickrey auction" format. It is great in theory but not what players are used to. Now I've found this format in the wild, first when I sold my home... 1/2 en.wikipedia.org/wiki/Vickrey...
en.wikipedia.org
Vickrey auction - Wikipedia
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Jonathan Tweet @jonathantweet.bsky.social · 01/09/2026
I can't find the paper that this refers to, and that's ok because this sound gross. How dare the lowly yeast use a prion protein to modulate an animal's physiology? Things are getting out of hand.
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Jonathan Tweet @jonathantweet.bsky.social · 01/09/2026
One nice thing about doing posters through Redbubble instead of running a crowd-funding campaign is that it's easy for people in other countries to get the poster. Much better than us trying to ship individual posters in tubes through international mail. We already had an order from Australia.
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Jonathan Tweet @jonathantweet.bsky.social · 01/09/2026
Played another adventure from Strange Stories by @strangestudies.bsky.social, and again we had a ton of fun with two players and me as the GM. These rules-light one-shots are just what my play group needs, and now I'm eagerly waiting for new adventures to get into the playtest loop.
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Shannon Appelcline @shannonappelcline.bsky.social · 01/09/2026
After a few test runs, I've published a 1.0 version of "The Rise & Call of Cthulhu", my evolutionary diagram of Call of Cthulhu gaming. I'll have an article talking about some of its interesting points later this week. timeline.designers-and-dragons.com/cthulhu.html
Unreadable thumbnail of The Rise & Call of the Cthulhu Empire, which shows the evolution of Cthulhu gaming.
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Jonathan Tweet @jonathantweet.bsky.social · 31/08/2026
If I'm right, this means that whole-genome duplications (such as with ancestral salmon) were the results of members of two species with slightly different genomes hybridizing. Am I right? I'm not sure.
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Jonathan Tweet @jonathantweet.bsky.social · 30/08/2026
Sugar sensing goes way back. Human life would be less pleasant without sugar sensing. Also I would weigh less.
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