The Summon
A command palette over your whole library. Fuzzy-search tables, monsters, and NPCs across every book you own — hit Space, type, done. No tab-hunting, no flipping.
A Dungeon Master Companion
Gnasher's Grimoire™
One book that holds all your books. Every Adventure Keeper, every pack, every free table you own — gathered into a single binder that sits on top of the adventure you're running. Press a key, type three letters, and summon any table, monster, or NPC from your whole library right over the scene. Roll it in place. Never lose your page.
One file · opens in your browser · works offline forever · no account, no install · comes loaded with the full SRD 5.2.1: 335 monsters, 339 spells, 620 items, the rules
The live build, in motion — Space → type → the table floats over The Keeper of Halcyon Light → rolled in place. This is a recording of the real app.
1
Press Space
Summon opens
A command line drops over whatever adventure you're running. Your scene stays exactly where it was.
2
Type 3 letters
Your whole library, searched
"wol", "d100", a villain's name — it fuzzy-searches every book you own at once. Tables, monsters, NPCs.
3
Enter
It floats. Roll it.
The table lands on top of your scene. Roll it right there, read the result, move on. You never left your place.
Think of it like a binder
Right now your adventures live scattered — a Keeper in your downloads, a free pack in your inbox, last week's one-shot in a folder you'll never find at the table. Gnasher's Grimoire is the slipcase that holds every one of them. Open the binder and it's all there: every table searchable, every monster one keystroke away, every NPC ready to speak.
It's the same instinct as a good DM screen — everything you need in arm's reach — except the reach is three letters and a keypress, and the screen holds your entire library instead of four cardboard panels.
You're not buying a PDF you scroll.
You're buying a Keeper that drops into your Grimoire.
What it does at the table
The moves you reach for mid-session, when you need something now and can't afford to lose the room.
The Board
Float as many cards as you want and drag them where you like. Collapse a big d100 down to its title bar — it still rolls collapsed. Everything saves to the exact adventure you opened it in.
Bookmarks
Drop up to ten spots in a long adventure — auto-named from the scene you're on ("Battle Map — Gull's Tooth"). Click a chip and you're back there instantly.
The War Table
Muster a fight from your party and any Creature Keeper you own — browsed like chapters — then run full initiative, HP, and conditions without leaving the page. Monster attacks roll right there.
Install your own
Drag a downloaded Keeper onto the binder and it's in — its tables and monsters join the Summon, its art streams in when you open it. No account, no upload, no sign-in.
The Live Table
Read one code off the screen and your players link in with Gnasher's Satchel. Muster a fight and initiative lights up every screen; push handouts and whispers; their rolls come home to your log. No server, no account.
Yours, offline, forever
Runs 100% offline, like the Keepers themselves. Your whole binder exports to one file you can back up or move. No subscription to open what you already own.
Every Keeper, one Grimoire
Everything the Long Island Dungeon Master makes is a Keeper — a self-contained file built to drop straight into your binder. Some are here now; more are on the forge. Every one lands in the same Summon and the same War Table.
Available nowAdventure KeepersFull interactive adventures — a whole night of play.
Available nowTable KeepersRandom tables for anything — roll and go.
On the forgeCreature KeepersMonsters & bestiaries, straight into the War Table.
On the forgeCharacter KeepersNPCs with a face, a want, and a voice.
On the forgeHazard KeepersTraps, hazards, and the perils that aren't alive.
On the forgeMap KeepersBattle maps that drop into any adventure.
On the forgeRelic KeepersMagic items & loot that come with a story.
On the forgeRealm KeepersDrop-in locations, ready with NPCs and hooks.
On the forgeChronicle KeepersKeepers woven into a full linked campaign.
More comingThe shelf keeps filling.
Gnasher's Grimoire
One Summon. One War Table. Your whole library, in reach — free.
An Adventure Keeper isn't a file you skim — it's a playable adventure that loads into your binder and runs. A Creature Keeper isn't a stat-block PDF — its monsters show up in the War Table, ready to fight. Own two Keepers and the Summon searches both. Own twenty and it searches twenty. The container is the value.
New · Run the fight in place
The War Table
The hardest part of a combat is never the dice — it's keeping the whole board in your head while the table watches you stall. The War Table runs it for you, right on top of the adventure.
- Muster from your party — split it, bring two of the six — and pull monsters from any Creature Keeper you own, grouped like chapters, with a quantity stepper ("3 orcs" auto-numbers them).
- Initiative & rounds tracked, one button to advance the turn.
- HP per combatant — type the damage, watch them drop.
- Conditions as removable chips, and monster attacks that roll to-hit and damage straight into your log.
New · Connect the whole table
The live table
You run the night from the Grimoire. Your players carry Gnasher's Satchel, the free character app, on their phones, tablets, or laptops. Pair once and the two halves lock together, with no server and no account.
- One code opens the table. Read it aloud, players type it in, and everyone is linked in seconds. No venue Wi-Fi? Same-room mode or a phone hotspot works too.
- Initiative drives every screen. When you muster a fight and advance turns on the War Table, each player's screen lights up on their turn. You do nothing extra.
- Push handouts and whispers. Send a map or a note to the whole table, or slip one player a private line.
- Their rolls come home. Player rolls land in your dice log and the session Chronicle, labeled by name.
- Phones sleep, seats are held. A dozing phone rejoins by itself and catches up on anything it missed.
Gnasher's GrimoireYou host the table
EMBER·42 paired
Nyx · RogueYour turn
Keros · DruidHandout received
Ruudak · WizardResting · held
The binder is free.
Gnasher's Grimoire is free, and it always will be — it's the shelf, and a shelf only matters once there's something on it. What you fill it with is up to you. Load it with free Table Keepers from The Hoard, then fill it with the Bi-Weekly One-Shots and Keepers when you want more teeth. Own more, summon more. That's the whole deal.
Free, forever
- Gnasher's Grimoire app itself
- The full SRD 5.2.1 reference, pre-installed: 335 monsters with an encounter builder, 339 spells, 620 items, classes, and the rules
- Tomes: drop in your own PDFs (a DriveThruRPG adventure, your notes) and they live on the shelf, open in the app, with page marks you set. They never leave your browser.
- The DM's Field Kit & Hoard tables
- Free Keepers — like Where the Road Ends
- Occasional free one-shots
- Install anything you download
New free content lands all the time — on the Substack and the socials.
Fill it when you want more
- Adventure Keepers — full adventures
- Creature Keepers — monsters for the War Table
- Character Keepers — NPCs, ready to speak
- Table Keepers — roll for anything
- The Bi-Weekly One-Shots
Find them on itch.io — with DriveThruRPG on the way.
First look
Screens from the live build. This is the app you're downloading.
Your ShelfEvery book you own, one binder
Roll in placeThe table floats over your scene
BookmarksTen spots, one keypress back
Take it — it's free
Gnasher's Grimoire is one file. Download it, double-click it, and you're holding a stocked binder: the full SRD 5.2.1 reference (335 monsters, 339 spells, 620 items, the rules, free under CC-BY-4.0), the DM's Field Kit, and a sample Adventure Keeper, all pre-loaded. Summon the Tarrasque from your very first keypress. No account. No install. No internet after this page. Then join The Bi-Weekly One-Shot and there's a new Keeper to feed it every other week.
Download Gnasher's Grimoire — free Join The Bi-Weekly One-Shot — freeWant to see what drops into it? Meet the Adventure Keepers — the self-contained adventures the Grimoire is built to hold — or grab free tools from The Hoard.
The companion line: Gnasher's Grimoire™ (DM app) · Gnasher's Satchel™ (player app) · Gnasher's Quill™ (session recorder).
the Quill records → the Grimoire holds → the Satchel carries.
Something broken, confusing, or missing? grimoire@longislanddungeonmaster.com or the LIDM Discord. It goes to me, and bad news is the useful kind.