The simulator

Project → Simulate Conversation… or F5 opens the simulator on the current conversation. The main window stays usable while it runs.

The window

Area	What it shows
Control toolbar (top centre)	Navigation and full-screen mode.
Stage (centre)	The speaking actor’s picture, the current line in the emphasis colours, and which audio file is playing. With no audio, the line stays on screen for a time computed from its length (see Subtitle speed).
Variable / Mutual Status / Relationship trackers (left)	Anything that changes during the run is added to the matching tracker automatically. Remove with the red ×; add by hand with the Track… Lua functions.
Last Executed Script / Script Errors (bottom)	The Lua that ran for the displayed node, and any errors.
Lua command line (bottom)	Run Lua against the live state. To display a value, write return Variable["points"]. ↑ / ↓ recall history.
Conversation Timer (top right)	Elapsed time, with pause / resume / reset.
Saved States (right)	Snapshots of every variable and asset field plus your position in the tree. A state is saved automatically each time a menu is shown, which is what makes back possible; name and save your own too. The V button loads only the variables from a state; the play button loads the whole state.
Possible Dialogue Choices (bottom right)	Every candidate from the current node: green passed its condition, red failed, with the condition text, its priority, its ID and its group number. This is the pane to read when a choice you expected is missing — and remember priorities compete only within a group.

Preferences (Tools → Preferences → Simulator Setup)

Setting	Effect
Lua command levels	How many command-line entries are kept for ↑ / ↓.
Auto save state levels	How many automatic saved states are kept.
Subtitle speed	Faster or slower on-screen time for lines with no audio.
Automatically track variables / mutual statuses / relationships	Add changes to the trackers without a Track… call.
Except SimStatus	Keep SimStatus changes out of the tracker.
Text-to-speech (1.8+)	Speak lines that have no audio file.

Equivalents in ChatMapper Cloud

The Cloud simulator has the transcript, the Variables panel, the Lua console (no return needed), and step back / forward in place of saved states. It does not yet show the possible-choices pane with condition results, or track mutual statuses and relationships; query them in the console.