JustilityDecision tree builder
Build decision and chance branches, enter payoffs and calculate risk-neutral expected values.
Build a decision and chance tree with comparable outcome payoffs. Evaluate expected values from the leaves to the root.
Up to 40 nodes and 80 connections on a 1200 × 900 canvas. Edit all content using the fields. Focus a diagram node and use arrow keys to move it (Shift = 30 units); dragging also works. Visual maps describe your model, not verified causation.
Your work stays in this tab. Nothing is saved automatically. Save a readable, unencrypted project file before closing. Downloads remain wherever you save them.
Processed on your device. Your files are never uploaded by Justility.
How privacy worksHow it works
Open decision tree builder, enter your own project details or load the labeled example, then edit nodes and connections and analyze the map. Review the results and download your project to continue later.
Supported formats
Editable JSON project up to 1 MB; SVG diagram and CSV analysis. Up to 40 nodes, 80 links, 120 characters per label and 1,200 per note.
Good to know
A single connected acyclic tree is required. Only leaf outcomes have payoffs.
Worked example
Before
Safe payoff 40; risky payoff 100 at 60% or −20 at 40%
After
Risky expected value 52; root chooses the risky branch
Decision nodes maximize comparable payoffs; chance probabilities must total 100%.
Decision tree builder: interpret the result
Build decision and chance branches, enter payoffs and calculate risk-neutral expected values. A single connected acyclic tree is required. Only leaf outcomes have payoffs. All project files are readable and unencrypted. Save and open them explicitly; there is no automatic browser persistence.
Argument mapping canvasTroubleshooting
Why will my decision tree not calculate?
Check that there is exactly one root, every node is connected, no node has two parents, and every chance node has probabilities totaling 100%.
Common questions
Can I use decision tree builder offline?
Prepare this tool using Offline help while online. After preparation, it runs locally with fresh input. Browser cache eviction remains possible; keep project downloads separately.
Can I use this without an internet connection?
Yes, after you prepare this tool from Offline help and the browser retains its assets. Installation is optional. All processing dependencies are bundled locally.