Character Vault
Any Concept / Any System
Your System Come To Life
Roll20 for Android
Streamlined for your Tablet
Roll20 for iPad
Streamlined for your Tablet

Personal tools

Sheet Author Tips

From Roll20 Wiki

Revision as of 22:15, 19 September 2020 by Andreas J. (Talk | contribs)

Jump to: navigation, search

Main Article: Building Character Sheets

This is a collection of more advanced Sheet Author Tips that doesn't fit the other pages. Most of the suggestions& ideas are taken from the forums.


Read the documentation

Give the Building Character Sheets-article a full read, as it contains lots of information on the specific quirks & pitfalls of how Roll20 character sheets works compared to default HTML/CSS/JavaScript. Even if you know how things work.

Some Highlights:

Custom Sheet Sandbox

Using the Sheet Sandbox while editing/developing character sheets is much more effective and quicker than the normal Sheet Editor.


Beyond just using HTML/CSS directly, you could use some pre-processors that can speed up the development, instead of directly writing HMTL/CSS. Here is a few suggestion, used by some sheet authors including Roll20 themselves.


Suggestion by Cassie

Use PUG & SCSS & JavaScript to make sheets. PUG & SCSS are the two most useful things I've ever learned for sheet development. Character sheets which use to take hundred+ hours takes now 20-40 thanks to PUG which is a Javascript based language to write HTML. You'll save yourself a lot of redundant work by just using the power of loops & variables if nothing else.

Troubleshooting becomes much easier when you need to fix just one line in a loop rather than a dozen copy/paste html snippets.

These are compiled languages so you'll need to do that. Easily done via terminal if your tech savy or if you're not.


Suggestion by Primal Zed

Forum thread


  • Looks like HTML (or whatever file type you're templating), with handlebars blocks added in
  • Inject data values anywhere directly into the HTML
  • Can yield benefit with little effort - sheet authors can use as much or as little as they want
  • Handlebars blocks have opening and close tags similar to HTML
  • Easy to add new templates for re-use and organization


  • Involves new syntax to learn and helpers to understand
    • Built-In Helpers
    • For advanced use: Additional Helpers
    • For advanced use: Repeat Helper
  • Requires Node.js installation and some command lines


Install Pull to GitHub

Pull is a GitHub bot GiGs found, and it can automatically keep your fork updated to Roll20 main repo.

So many pull request get rejected or delayed due to a failure to keep GitHub forks in sync with the master repo. This will automate that for you.

It's recommended to manually run the bot before each time you start on a new thing, to avoid it performing updates when Roll20 is in the middle of merging new pull requests. This caused lot of problems when people had it to automatically update repos.

Use Branches in GitHub

Do not make changes to your GitHub master. Instead make a branch from master to do all upgrades there. Submit pull request to the Roll20 repo directly from a branch. This is a safe way to do version control and will improve the integrity of your work.

Pattern Libraries & Components

Suggestion by Cassie

A pattern library can be your best friend if you want to make multiple sheets. Component style programming will let you save styles to be reused between sheets. With my last project I put work into my Sheet Template. This saves me a good deal of time by not needing to start from scratch every time. Its a slow work in progress were I'm reinventing much of Bootstrap.

Helpful Functions

//Convert Integers to be Negative
const convertIntegerNegative = number => number > 0 ? -Math.abs(number) : number

//Convert an object with negative numbers
const convertIntegersNegatives = numbers => {
  numbers => {
    for (let [key, value] of Object.entries(numbers)) {
      numbers[key] = convertIntegerNegative(value);
    return numbers

//Pass in eventinfo.triggerName
const findRepeatingField = trigger => trigger.split('_')[1]

//Pass in eventinfo.triggerName
const getReprowid = trigger => {
  const split = trigger.split('_');
  return `${split[0]}_${split[1]}_${split[2]}`

//Pass in an object keep that has the repeating section
//Example repeating_weapon_-m1czg68yzicwhfdpyys_name
const getReprowAttribute = key => {
  const getReprowid = processingFunctions.getReprowid(key)
  return key.split(`${getReprowid}_`)[1]

//Provide the function with an array of keys to find transations for 
//Example ['strenght', 'agility', 'willpower']
const getTranslations = translationKeys => {
  let translations = {}
  translationKeys.forEach(key => translations[`${key}`] = getTranslationByKey(key))
  return translations

const parseInteger = string => parseInt(string) || 0

//Use for convernting the result of getAttrs from strings into integers
const parseIntegers = numbers => {
  for (let [key, value] of Object.entries(numbers)) {
      numbers[key] = parseInt(value) || 0
  return numbers  

const setAttributes = (update, silent) => silent && typeof update === 'object' ? setAttrs(update, {silent:true}) : typeof update === 'object' ? setAttrs(update) : console.error(`${update} is not an object`)

//returns strength from @{strenght}
const sliceAttr = attribute => attribute.slice(2, -1)

const sumIntegers = numbers => numbers.reduce((a,b) => a + b, 0)

Sheet Versioning

It can be beneficial to use a visible sheet version on a sheet, so people know when the sheet have updated. Also using sheet version will make it easier for you and others to track the state of the sheet and possible changelog.

If you have complex stat & sheetworkers in you sheet and make changes to them, it can be beneficial to add sheet versioning sheetworker that updates things for character using older version of the sheet to a new one.

An example would be to update an attribute name with a typo, to one with the correct spelling. The sheet versioning would next time a sheet is opened notice it is a older version, and then perform the sheet update transferring the attribute values of the old attribute to the new one, while it would do nothing on sheet that are already the latest version.

Forum post by GiGs, explaining a sheet versioning script, found in this gistGitHubLogo.png

Improved Sheetworker diagnostics

TheAaronSheet contains a number of helpful sheetworker functions like simplifying repeating sections, but it also has a improved debugging settings that can help making various dev console messages more distinct.

Sheet Changelog and notification

The GURPS sheet displaying the latest sheet update notice.

If you a lots of changes to a sheet, or want to make sure that the users of the sheet are informed of the updates, you could integrate the sheet changelog & notice into the sheet, so everyone will know of the changes, & can dismiss them at will. Alternatively the changelog can be placed on a tab somewhere

The team behind the GURPS character sheet is an example of incorporating a comprehensive changelog into the sheet, with a collapsible notice of the latest update/message from the sheet authors.


The "instructions" section of the sheet.json is a bit unwieldy to fill out, so it might be easier to place any larger documentation here on the Roll20 Wiki.

If the character sheet have several tabs or is long, the wiki could better fit more preview images of the sheet rather than having something complicated on github.

Sharing code/collaboration

If you need to share larger parts of a sheets code with others on the Roll20 forums or somewhere else quickly, using GitHub Gist to share the full sheet is a smart alternative to Dropbox/Google Drive/Pastebin.

The "Revisions" tab of a gist shows clearly code changes between revisions, so tracking what have changed makes things easier for you and others.

See Also