Node Types
Every node in the Logic Editor belongs to a category. You can find them in the sidebar panel on the left side of the canvas. Drag any node from the sidebar onto the canvas to add it to your graph.
Each node has inputs (on the left side) and outputs (on the right side). You connect an output from one node to an input on another to pass data between them.
Variables
Variable nodes are your starting points. They provide data to the rest of your graph — either by reading values from the character sheet or by supplying a fixed number or text value.
| Node | Inputs | Outputs | What It Does |
|---|---|---|---|
| Attribute | Value (optional) | Value | Reads a character sheet attribute by name. If you connect something to its input, it writes that value back to the attribute instead. This is how calculated results get saved to the sheet. |
| Number | — | Value | Outputs a fixed number that you set (e.g., 10, 2, 20). Use these for constants in your formulas. |
| String | — | Value | Outputs a fixed piece of text that you set. Useful for labels, default values, or text that doesn't change. |
The Attribute node is the bridge between the Logic Editor and your character sheet. Every formula you build will start by reading from attributes and end by writing results back to them.
Read vs. Write mode: The Attribute node changes behavior depending on whether its input is connected. With nothing connected to its input, it reads the attribute value and sends it out its output port. With something connected to its input, it writes the incoming value to that attribute on the character sheet. You can tell which mode it is in by looking at the connections: an Attribute node at the start of a chain (no incoming wire) is reading; one at the end of a chain (wire coming into its input) is writing.
Attributes correspond to the fields you have placed in the Layout Editor. The Attribute node gives you a dropdown of all available attribute names, so you don't have to remember them.
Interaction
Interaction nodes connect your logic to things the player does — clicking buttons and rolling dice.
| Node | Inputs | Outputs | What It Does |
|---|---|---|---|
| Button | — | On Click | Fires a signal when the player clicks a specific button on the sheet. Use this as a trigger to start a chain of logic. You select which button from a dropdown of buttons in your layout. |
| Roll / Message | Trigger, plus one input per field | — | Performs a dice roll or sends a message to chat using a roll template. You write a template string and define fields that get filled in by connected values. |
The Roll / Message node is where your logic meets the dice. You write a message template using Roll20's syntax — for example, &{template:default} {{name=Attack}} {{roll=[[1d20+@{attack_bonus}]]}}. Each {{field}} you reference in the template automatically creates an input on the node that you can connect to other nodes.
If you have used roll templates in Roll20 macros before, the same syntax works here. You can also use inline rolls like [[1d20+5]] inside your template text.
Math
Math nodes perform arithmetic. If you have ever written a formula in a spreadsheet, these will feel familiar.
| Node | Inputs | Outputs | What It Does |
|---|---|---|---|
| Add | Values | Result | Adds all connected values together. You can connect as many inputs as you like — they all get summed. |
| Subtract | A, B, C... | Result | Subtracts in order: A - B - C and so on. The order matters, so inputs are labeled. A new input appears each time you connect one. |
| Multiply | Values | Result | Multiplies all connected values together. Like Add, accepts multiple connections to a single input. |
| Divide | A, B, C... | Result | Divides in order: A / B / C. The order matters. |
| Floor | Value | Result | Rounds a number down to the nearest whole number. 2.9 becomes 2. This is what D&D means by "round down." |
| Ceil | Value | Result | Rounds a number up to the nearest whole number. 2.1 becomes 3. |
| Round | Value | Result | Rounds to the nearest whole number. 2.5 rounds to 3, 2.4 rounds to 2. |
| Abs | Value | Result | Returns the absolute value — strips the negative sign if there is one. -3 becomes 3. |
| Min | Values | Result | Returns the smallest value among all connected inputs. Useful for capping a value (e.g., "HP can't exceed max HP"). |
| Max | Values | Result | Returns the largest value among all connected inputs. Useful for setting floors (e.g., "modifier is at least 0"). |
Add, Multiply, Min, and Max accept any number of connections to the same input. Just drag multiple wires to the "Values" input and they all get processed together.
Subtract and Divide care about order, so they give each connection its own labeled slot (A, B, C...). A new slot appears automatically when you fill the last one.
Logic
Logic nodes let you make decisions — comparing values and choosing different paths based on conditions.
| Node | Inputs | Outputs | What It Does |
|---|---|---|---|
| Compare | A, B | Result | Compares two values using an operator you choose: equals, not equals, greater than, less than, greater or equal, or less or equal. Outputs true or false. |
| Logic Gate | A, B | Result | Combines two true/false values using AND (both must be true), OR (at least one must be true), or XOR (exactly one must be true, not both). You pick the mode from a dropdown on the node. |
| If / Else | Condition | Then, Else | Routes data based on a condition. If the condition is true, data flows out the "Then" output. If false, it flows out the "Else" output. Connect a Compare or Logic Gate node to the Condition input. |
Example: Conditional Proficiency Bonus
Here is a common pattern for applying a proficiency bonus only when a skill is marked as proficient:
- Use a Compare node to check if
athletics_proficiencyequals1. - Connect the result to an If / Else node's Condition input.
- On the "Then" side, connect your proficiency bonus value.
- On the "Else" side, connect a Number node set to
0. - Connect the If / Else output to the rest of your skill bonus calculation.
The result: proficient characters get the bonus, non-proficient characters get zero.
Data
Data nodes handle text manipulation and type conversion.
| Node | Inputs | Outputs | What It Does |
|---|---|---|---|
| Concatenate | A, B, C... | Result | Joins text strings together in order. For example, connecting "Attack: " and a damage value produces "Attack: 8". New inputs appear as you connect them, just like Subtract. |
| Parse Number | String | Number | Converts a text value to a number. If an attribute stores "14" as text, this turns it into the number 14 so you can do math with it. |
| Repeating Section | — | Items | Connects to a repeating section in your layout — things like inventory rows, spell lists, or attack entries where the player can add and remove rows. You select which repeating section from a dropdown. The output provides access to the attributes within each row, which you can then process in your logic. |
Repeating sections on Roll20 are fields that the player can add multiple copies of — like rows in an inventory table or entries in a spell list. The Repeating Section node lets your logic interact with all the rows in one of these sections. The output carries the row data so you can read attributes from each row and perform calculations across all rows (such as summing total weight from all inventory items). See the Roll20 wiki on repeating sections for background on how they work.
Groups
Group nodes help you organize complex graphs and handle repetitive patterns efficiently.
| Node | Inputs | Outputs | What It Does |
|---|---|---|---|
| Logic Group | — | — | A visual container you can place around a set of nodes to keep them organized. You can name it, color it, and collapse it. Has no effect on calculations — purely organizational. |
| Batch Processor | Varies | Varies | Processes the same formula across multiple data points at once. Instead of building the same node chain 6 times for 6 ability scores, you define the pattern once and the Batch Processor applies it to all of them. See Groups and Batches for a full walkthrough. |
Batch Processors are one of the most powerful features in the Logic Editor. If you find yourself building the same chain of nodes more than twice, a batch node will save you significant time and keep your graph clean.
Custom
For advanced users who need capabilities beyond the built-in nodes.
| Node | Inputs | Outputs | What It Does |
|---|---|---|---|
| Script | Input | Output | Runs a custom JavaScript function. The connected input value is available inside the script, and whatever you return becomes the output. This is an advanced feature — you will need some familiarity with JavaScript to use it. |
The Script node is an escape hatch for edge cases. If you find yourself reaching for it frequently, check whether a combination of built-in nodes can do the job first — built-in nodes are easier to maintain and less error-prone.