The 5e to Nimble Monster Converter (Beta)

If you play Nimble RPG and come from a D&D 5e background, you already know the problem: there is a massive library of 5e monsters out there — in sourcebooks, on D&D Beyond, in adventure modules — and none of them are usable out of the box in Nimble. Converting them by hand is doable, but it takes time, especially when you are trying to prep a session quickly.

That is why I built the 5e to Nimble Monster Converter, a free browser-based tool that takes a 5e stat block as input and outputs a ready-to-use Nimble 2e stat block. No account, no install, nothing to download.

It is currently in beta, which means it works well for most common monsters but still has rough edges. This article walks through how to use it, what the output looks like, what its current limits are, and — most importantly — how you can help make it better.

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A Quick Word on Nimble RPG

Nimble is a streamlined, action-focused TTRPG designed for fast-paced combat and easy GMing. Where 5e monsters have long stat blocks full of saving throws, skill bonuses, and multiple ability scores, Nimble monsters are built around a tight set of values:

• Level — the monster’s tier, roughly equivalent to CR
• HP — scaled to the monster’s level and armor type
• Armor Type — No Armor, Medium Armor, or Heavy Armor (replaces AC)
• Save DC — a single number for all saves
• Actions — streamlined attacks with damage and movement
• Abilities — a small list of special traits with defined triggers
• Bloodied — an optional effect that triggers at half HP
• Last Stand — an optional final action when the monster would die

This design makes monsters much faster to run, which is the whole point. The converter bridges the gap between the rich 5e monster library and this cleaner format.

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How to Use the Tool

Head to solorpgstudio.com/tools/5e-to-nimble-monster-converter. You will see two panels: the input on the left and the Nimble output on the right.

Input Method 1 — Paste Text

The Paste Text tab is the fastest way to convert a monster. Copy a stat block from D&D Beyond, a PDF, Roll20, or any other source, paste it into the text area, and hit Convert.

The tool will attempt to extract:

• Name, size, and creature type
• Armor Class → used to determine Nimble armor type
• Hit Points
• Speed
• Challenge Rating → used to look up the Nimble level and damage targets
• Ability scores (STR, DEX, CON, INT, WIS, CHA) if present
• Actions and attacks
• Special traits like Pack Tactics, Multiattack, or Regeneration

Tips for best results:

• The parser handles both the classic 5e format (+5 to hit) and the 2024 revised format (Attack Roll: +5)
• Include the CR line — it is what drives most of the conversion math
• Keeping the stat block close to the original format (not heavily reformatted) improves parsing accuracy
• Use the Load Example button to see what a well-formatted input looks like

Input Method 2 — Manual Form

If the text parser struggles with a specific stat block (or you just prefer structured input), switch to the Manual Form tab. You fill in each field directly:

• Name, size, and creature type from dropdowns
• AC, HP, and Speed as numbers
• CR from a dropdown (1/8 through 20)
• Actions one at a time, with name, damage dice, damage type, and reach

This method gives you full control and is more reliable than text parsing for unusual or heavily formatted stat blocks.

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Understanding the Conversion

Once you hit Convert, the tool runs through several steps to build the Nimble stat block.

CR → Nimble Level

The Challenge Rating is mapped to a Nimble Level using a conversion table based on Nimble’s Monster Builder guidelines. This determines the baseline HP values and the expected damage per round.

5e CR	Nimble Level
1/8	1/4
1/4	1/3
1/2	1/2
1	1
5	5
10	10
20	20

AC → Armor Type

The monster’s Armor Class is mapped to one of Nimble’s three armor tiers:

5e AC	Nimble Armor Type
1–12	No Armor
13–15	Medium Armor
16+	Heavy Armor

This also affects HP: a No Armor monster has significantly more HP than a Heavy Armor one at the same level, following Nimble’s design intention that tankier monsters trade HP for defense.

Damage

Rather than carrying over raw 5e damage dice, the tool uses Nimble’s recommended damage-per-round targets for each level. The output damage dice are chosen to match that target as closely as possible. This keeps the monster balanced within the Nimble system rather than just copy-pasting 5e numbers.

Auto-Detected Options

After parsing, the tool runs an analysis pass and automatically suggests options based on the stat block content:

• Solo — auto-enabled for CR 5+ monsters, which benefit from Nimble’s solo rules
• Bloodied — auto-enabled for CR 1+, generating a type-appropriate bloodied effect
• Last Stand — auto-enabled for CR 10+, generating a final action flavor text
• Abilities — the tool scans for keywords (pack tactics, grapple, fear, poison, fly speed, etc.) and suggests matching Nimble abilities from the full list

These are all suggestions. You can override every single one.

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The Output Panel

Options

Before looking at the stat block output, the Options panel lets you fine-tune the conversion:

• Solo Monster — adds the Solo designation, relevant for Nimble’s encounter rules
• Include Bloodied — adds a triggered effect at half HP; you can write a custom one or use the auto-generated version
• Include Last Stand — adds a final action before death; same custom/auto choice
• Monster Abilities — browse the full Nimble ability list (40+ abilities across offensive, defensive, movement, control, and special categories), see what was auto-suggested for the creature type, and toggle any on or off

Any change to these options instantly regenerates the stat block — no need to re-convert.

Card View vs. Detailed View

The output offers two views:

Card View renders the monster as a Nimble stat card — the parchment-style format with HP and Speed icons, passive ability banners, and a footer with armor type and Save DC. This view matches the visual format of official Nimble monster cards and is what you would want to screenshot or save.

Detailed View shows the same data in a clean text layout that is easier to read at a glance during a session.

Export Options

Once you have a result you are happy with:

• Copy to Clipboard — copies a plain text version of the stat block
• Download Markdown — saves a .md file, useful for VTT notes or Obsidian vaults
• Download JSON — saves a .json file if you want to process the data further
• Save as Image — captures the card view as a high-resolution PNG, ready to drop into a VTT, print, or share

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Current Limitations

This is a beta. Here is what works well and what does not yet.

Works well:

• Standard 5e monster formats from D&D Beyond, the SRD, and most published adventures
• Both the 2014 and 2024 revised stat block formats
• Creatures with clear attack lines and standard ability score layouts
• CR 1/8 through 20

Known rough spots:

• Stat blocks copied from PDFs sometimes have irregular spacing or line breaks that confuse the parser — the Manual Form tab is a reliable workaround
• Multiattack is detected but not fully decomposed; the converter uses a single representative action
• Legendary actions and lair actions are not yet parsed
• Spellcasting blocks are noted but not converted to Nimble equivalents
• Some fringe CR values (like CR 0) may not map cleanly

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How to Help During the Beta

Every piece of feedback makes the tool better. Here is how you can contribute:

Report Bugs and Request Features

If you find a stat block that does not parse correctly, or if there is a 5e monster feature you wish the converter handled, open an issue on GitHub. Include the stat block text you tried to convert and describe what you expected versus what you got. Feature requests are equally welcome — if there is a Nimble ability or export format missing, say so.

Share the Tool

The more people use it, the more edge cases get discovered. If you know someone who plays both 5e and Nimble, or who GMs for a group and needs to prep monsters quickly, share the tool with them. A link in a Discord, a mention in a forum thread, or a share on social media goes a long way.

Support the Project

Building and maintaining tools like this takes real time. If the converter has saved you prep time or helped you run a better session, consider buying me a coffee. It directly helps keep the site running and new features coming.

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What Is Coming Next

The converter is the first tool on Solo RPG Studio, but it will not be the last. On the roadmap for this tool specifically:

• Better parsing for spellcasting stat blocks
• Legendary action support
• An encounter builder that uses converted Nimble monsters
• A shareable link so you can send a converted stat block directly to someone

If you have a specific request, open an issue and it goes straight onto the list.

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The goal is simple: make it easier to bring great 5e monsters to the Nimble table without spending your prep time on manual conversion. Try the tool, break it, tell me what is wrong, and help make it something worth sharing.