diff --git a/src/app/editor.rs b/src/app/editor.rs
index 94e083a..7d1d090 100644
--- a/src/app/editor.rs
+++ b/src/app/editor.rs
@@ -5,6 +5,32 @@ use super::*;
 
 impl App {
     pub(super) fn editor(&mut self, ui: &mut egui::Ui) {
+        // The bundled scene template is a reference writers copy from by
+        // hand, not something the app reads — so an edit to it just sits
+        // there, invisible, until someone notices the scene they copied from
+        // it looks wrong. Lock it against typing until explicitly unlocked.
+        let is_template = self
+            .selected
+            .and_then(|i| self.files.get(i))
+            .is_some_and(|f| workspace::is_template_file(f));
+        let locked = is_template && !self.template_unlocked;
+        if is_template {
+            ui.horizontal(|ui| {
+                if locked {
+                    ui.label("🔒 This is the scene template — locked to prevent accidental edits.");
+                    if ui.button("Unlock").clicked() {
+                        self.template_unlocked = true;
+                    }
+                } else {
+                    ui.label("🔓 Unlocked for editing.");
+                    if ui.button("Lock").clicked() {
+                        self.template_unlocked = false;
+                    }
+                }
+            });
+            ui.add_space(4.0);
+        }
+
         // Base monospace size scaled by the zoom percentage. `desired_width` stays
         // infinite and the scroll area is vertical-only, so text wraps to the pane
         // width at any zoom (no horizontal scrolling).
@@ -113,6 +139,7 @@ impl App {
                     .desired_width(f32::INFINITY)
                     .desired_rows(rows)
                     .layouter(&mut layouter)
+                    .interactive(!locked)
                     .show(ui);
                 if output.response.changed() {
                     self.dirty = true;
diff --git a/src/app/mod.rs b/src/app/mod.rs
index 35c69fc..bc180ab 100644
--- a/src/app/mod.rs
+++ b/src/app/mod.rs
@@ -209,6 +209,11 @@ pub struct App {
     /// The editorial header lifted out of `buffer` while it is collapsed.
     header_stash: Option<String>,
     dirty: bool,
+    /// Whether the currently open `_template.md` has been unlocked for
+    /// editing this session. Not persisted and not file-specific — it resets
+    /// to locked whenever a different file is selected, so re-opening the
+    /// template always starts protected again.
+    template_unlocked: bool,
     /// Byte offset of the primary cursor in `buffer`, as of the last frame.
     /// Used by typewriter mode to notice the cursor moved (and re-center it)
     /// versus the writer scrolling the view manually, and to find the current
@@ -509,6 +514,7 @@ impl App {
             buffer: String::new(),
             header_stash: None,
             dirty: false,
+            template_unlocked: false,
             cursor_pos: 0,
             new_name: String::new(),
             rename_input: String::new(),
diff --git a/src/app/workspace.rs b/src/app/workspace.rs
index a4e5c48..5b34d27 100644
--- a/src/app/workspace.rs
+++ b/src/app/workspace.rs
@@ -615,6 +615,8 @@ impl App {
         self.selected = Some(idx);
         self.dirty = false;
         self.pending_delete = false;
+        // A lock earned on one file doesn't carry over to the next.
+        self.template_unlocked = false;
         // Update Story Bible references for the newly selected file
         self.update_current_references();
         // The rename box holds the whole workspace-relative path, so it doubles
@@ -1914,6 +1916,16 @@ pub(super) fn render_template(template: &str, stem: &str, marker: &str, date: &s
     out
 }
 
+/// Whether `path` is the bundled scene template (`_template.md`): a reference
+/// file writers open to see the expected header fields and copy from by hand,
+/// not something the app reads from — "New from template" instead pulls from
+/// [`Config::new_file_template`](crate::config::Config::new_file_template).
+/// Easy to edit by mistake while skimming it, so the editor locks it against
+/// changes until explicitly unlocked — see [`App::editor`](super::App::editor).
+pub(super) fn is_template_file(path: &str) -> bool {
+    base_name(path).eq_ignore_ascii_case("_template.md")
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -2097,6 +2109,21 @@ mod tests {
         assert_eq!(render_template("a\n{{marker}}\nb\n", "n", "", "d"), "a\n\nb\n");
     }
 
+    #[test]
+    fn is_template_file_matches_only_the_scene_template_by_name() {
+        assert!(is_template_file("_template.md"));
+        assert!(is_template_file("05-First Draft/_template.md"));
+        // Case-insensitive, like the file system it's read from.
+        assert!(is_template_file("05-First Draft/_TEMPLATE.MD"));
+        // A chapter folder could have its own copy — still matches by name.
+        assert!(is_template_file("Act 1/Chapter 2/_template.md"));
+        // Other underscore-prefixed files (chapter info, notes) aren't it.
+        assert!(!is_template_file("_chapter.md"));
+        assert!(!is_template_file("_notes.md"));
+        assert!(!is_template_file("scene01.md"));
+        assert!(!is_template_file("template.md"));
+    }
+
     /// The point of the default template is that the app's own header parser
     /// understands what it produces — otherwise the seeded fields are just text.
     #[test]