diff --git a/locales/ar-SA/opencadstudio.ftl b/locales/ar-SA/opencadstudio.ftl
index 1bdca29d6..99a821bea 100644
--- a/locales/ar-SA/opencadstudio.ftl
+++ b/locales/ar-SA/opencadstudio.ftl
@@ -6620,3 +6620,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/bg-BG/opencadstudio.ftl b/locales/bg-BG/opencadstudio.ftl
index 01d6458d0..528e8ea27 100644
--- a/locales/bg-BG/opencadstudio.ftl
+++ b/locales/bg-BG/opencadstudio.ftl
@@ -6608,3 +6608,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/cs-CZ/opencadstudio.ftl b/locales/cs-CZ/opencadstudio.ftl
index 641d25bde..382990834 100644
--- a/locales/cs-CZ/opencadstudio.ftl
+++ b/locales/cs-CZ/opencadstudio.ftl
@@ -6605,3 +6605,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/de-DE/opencadstudio.ftl b/locales/de-DE/opencadstudio.ftl
index fabe8978e..11d1488bd 100644
--- a/locales/de-DE/opencadstudio.ftl
+++ b/locales/de-DE/opencadstudio.ftl
@@ -6606,3 +6606,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/el-GR/opencadstudio.ftl b/locales/el-GR/opencadstudio.ftl
index 2909b23af..b2a8b4c96 100644
--- a/locales/el-GR/opencadstudio.ftl
+++ b/locales/el-GR/opencadstudio.ftl
@@ -6608,3 +6608,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/en-US/opencadstudio.ftl b/locales/en-US/opencadstudio.ftl
index 152cc6375..318730cea 100644
--- a/locales/en-US/opencadstudio.ftl
+++ b/locales/en-US/opencadstudio.ftl
@@ -6607,3 +6607,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/es-ES/opencadstudio.ftl b/locales/es-ES/opencadstudio.ftl
index 2104bc40c..531f8c66c 100644
--- a/locales/es-ES/opencadstudio.ftl
+++ b/locales/es-ES/opencadstudio.ftl
@@ -6608,3 +6608,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: introduce 0 (conservar vista) o 1 (seguir SCP) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activa una ventana de modelo; no se aplica al espacio papel.
     .invalid = UCSFOLLOW: solo se permite 0 o 1.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/fi-FI/opencadstudio.ftl b/locales/fi-FI/opencadstudio.ftl
index dadf2e21e..88499a240 100644
--- a/locales/fi-FI/opencadstudio.ftl
+++ b/locales/fi-FI/opencadstudio.ftl
@@ -6605,3 +6605,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/fr-FR/opencadstudio.ftl b/locales/fr-FR/opencadstudio.ftl
index 2bb29a725..dca7b0895 100644
--- a/locales/fr-FR/opencadstudio.ftl
+++ b/locales/fr-FR/opencadstudio.ftl
@@ -6608,3 +6608,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/hi-IN/opencadstudio.ftl b/locales/hi-IN/opencadstudio.ftl
index 775ce9d2d..a0d4f3060 100644
--- a/locales/hi-IN/opencadstudio.ftl
+++ b/locales/hi-IN/opencadstudio.ftl
@@ -6596,3 +6596,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/hu-HU/opencadstudio.ftl b/locales/hu-HU/opencadstudio.ftl
index dacea1c4c..4b497a1c8 100644
--- a/locales/hu-HU/opencadstudio.ftl
+++ b/locales/hu-HU/opencadstudio.ftl
@@ -6592,3 +6592,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/it-IT/opencadstudio.ftl b/locales/it-IT/opencadstudio.ftl
index ec7e22f51..585a3cae0 100644
--- a/locales/it-IT/opencadstudio.ftl
+++ b/locales/it-IT/opencadstudio.ftl
@@ -6607,3 +6607,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/ja-JP/opencadstudio.ftl b/locales/ja-JP/opencadstudio.ftl
index f11fc5204..8b768c62e 100644
--- a/locales/ja-JP/opencadstudio.ftl
+++ b/locales/ja-JP/opencadstudio.ftl
@@ -6596,3 +6596,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/ko-KR/opencadstudio.ftl b/locales/ko-KR/opencadstudio.ftl
index d010218d4..d96d7a167 100644
--- a/locales/ko-KR/opencadstudio.ftl
+++ b/locales/ko-KR/opencadstudio.ftl
@@ -6607,3 +6607,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/lo-LA/opencadstudio.ftl b/locales/lo-LA/opencadstudio.ftl
index 0156752fd..26732ea02 100644
--- a/locales/lo-LA/opencadstudio.ftl
+++ b/locales/lo-LA/opencadstudio.ftl
@@ -6608,3 +6608,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/nl-NL/opencadstudio.ftl b/locales/nl-NL/opencadstudio.ftl
index 42c14ea0c..021b22467 100644
--- a/locales/nl-NL/opencadstudio.ftl
+++ b/locales/nl-NL/opencadstudio.ftl
@@ -6606,3 +6606,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/pl-PL/opencadstudio.ftl b/locales/pl-PL/opencadstudio.ftl
index 35cfbf57f..e8ff9d4a4 100644
--- a/locales/pl-PL/opencadstudio.ftl
+++ b/locales/pl-PL/opencadstudio.ftl
@@ -6607,3 +6607,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/pt-BR/opencadstudio.ftl b/locales/pt-BR/opencadstudio.ftl
index c49e81d75..bf5c64b9e 100644
--- a/locales/pt-BR/opencadstudio.ftl
+++ b/locales/pt-BR/opencadstudio.ftl
@@ -6608,3 +6608,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/ru-RU/opencadstudio.ftl b/locales/ru-RU/opencadstudio.ftl
index 683169314..c25ebccbf 100644
--- a/locales/ru-RU/opencadstudio.ftl
+++ b/locales/ru-RU/opencadstudio.ftl
@@ -6609,3 +6609,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/tr-TR/opencadstudio.ftl b/locales/tr-TR/opencadstudio.ftl
index 6cf148f60..4f8e88cf4 100644
--- a/locales/tr-TR/opencadstudio.ftl
+++ b/locales/tr-TR/opencadstudio.ftl
@@ -6529,3 +6529,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Oluşturduktan sonra blok düzenleyicide aç
+    .remembered = Ekranda belirt, nesne seçeneği, dağıtmaya izin ve bu anahtar sonraki açılışta hatırlanır.
+    .no-objects = Blok için nesne seçilmedi.
+    .create-empty = Boş blok oluştur
diff --git a/locales/zh-CN/opencadstudio.ftl b/locales/zh-CN/opencadstudio.ftl
index 384adc93c..fbb6a693b 100644
--- a/locales/zh-CN/opencadstudio.ftl
+++ b/locales/zh-CN/opencadstudio.ftl
@@ -6591,3 +6591,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/locales/zh-TW/opencadstudio.ftl b/locales/zh-TW/opencadstudio.ftl
index 9afc4ece7..b33d8b1f2 100644
--- a/locales/zh-TW/opencadstudio.ftl
+++ b/locales/zh-TW/opencadstudio.ftl
@@ -6603,3 +6603,9 @@ ucs-follow =
     .prompt = UCSFOLLOW: enter 0 (keep view) or 1 (follow UCS) <__ocs_fmt_0__>:
     .paper-space = UCSFOLLOW: activate a model viewport; paper space cannot follow the UCS.
     .invalid = UCSFOLLOW: only 0 or 1 is allowed.
+
+block-def-dialog =
+    .open-in-editor = Open in block editor after creating
+    .remembered = Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time.
+    .no-objects = No objects are selected for the block.
+    .create-empty = Create empty block
diff --git a/src/app/command_driver/entity_commit.rs b/src/app/command_driver/entity_commit.rs
index 6efce0043..559961a35 100644
--- a/src/app/command_driver/entity_commit.rs
+++ b/src/app/command_driver/entity_commit.rs
@@ -810,6 +810,14 @@ impl OpenCADStudio {
                 self.refresh_properties();
                 self.note_recent_block(&name);
                 self.refresh_block_palette();
+                // The Block Definition dialog asked to edit the new block.
+                if self
+                    .block_definition_open_editor
+                    .take()
+                    .is_some_and(|wanted| wanted.eq_ignore_ascii_case(&name))
+                {
+                    return Some(self.dispatch_command(&format!("BEDIT_OPEN:{name}")));
+                }
             }
             Err(err) => {
                 self.discard_last_undo_entry(i);
diff --git a/src/app/commands/blocks.rs b/src/app/commands/blocks.rs
index e59fdbb38..a10432569 100644
--- a/src/app/commands/blocks.rs
+++ b/src/app/commands/blocks.rs
@@ -61,7 +61,11 @@ impl OpenCADStudio {
             remembered.objects_on_screen = state.objects_specify_onscreen;
             remembered.mode = state.object_mode;
             remembered.allow_exploding = state.allow_exploding;
+            remembered.open_in_editor = state.open_in_editor;
         }
+        self.block_definition_open_editor = state
+            .open_in_editor
+            .then(|| state.name.trim().to_string());
         self.persist_settings_if_changed();
         let i = self.active_tab;
         let base_point = state.parse_base_point();
@@ -122,6 +126,59 @@ impl OpenCADStudio {
         )
     }
 
+    /// Draw the selected objects, or else the existing definition the name
+    /// picks, in the Block Definition dialog's name card.
+    pub(in crate::app) fn refresh_block_definition_preview(&mut self) {
+        let scene = &self.tabs[self.active_tab].scene;
+        let Some(state) = self.block_definition.as_mut() else {
+            return;
+        };
+        state.preview = if state.selected_handles.is_empty() {
+            let name = state.name.trim();
+            state
+                .existing_names
+                .iter()
+                .find(|existing| existing.eq_ignore_ascii_case(name))
+                .map(|existing| scene.block_preview_wires(existing))
+                .unwrap_or_default()
+        } else {
+            state.empty_prompt = false;
+            let mut wires = Vec::new();
+            for handle in &state.selected_handles {
+                match scene.document.get_entity(*handle) {
+                    // A reference is drawn from its definition, placed by the
+                    // reference's transform.
+                    Some(codec::EntityType::Insert(insert)) => {
+                        let base = crate::scene::render_graph::block_base_point(
+                            &scene.document,
+                            &insert.block_name,
+                        );
+                        let xform =
+                            crate::scene::render_graph::insert_transform_with_base(insert, base);
+                        for mut wire in scene.block_preview_wires(&insert.block_name) {
+                            for p in &mut wire.points {
+                                if p.iter().all(|v| v.is_finite()) {
+                                    let q = xform.apply(codec::types::Vector3::new(
+                                        f64::from(p[0]),
+                                        f64::from(p[1]),
+                                        f64::from(p[2]),
+                                    ));
+                                    *p = [q.x as f32, q.y as f32, q.z as f32];
+                                }
+                            }
+                            wires.push(wire);
+                        }
+                    }
+                    Some(entity) => {
+                        wires.extend(scene.wires_for_entities(std::slice::from_ref(entity)))
+                    }
+                    None => {}
+                }
+            }
+            wires
+        };
+    }
+
     pub(super) fn dispatch_blocks(&mut self, cmd: &str, i: usize) -> Option<Task<Message>> {
         match cmd {
             // ── BASE — drawing insertion base point ───────────────────────
@@ -469,6 +526,7 @@ impl OpenCADStudio {
                     ),
                 );
                 self.active_modal = Some(crate::app::ModalKind::BlockDefinition);
+                self.refresh_block_definition_preview();
             }
 
             cmd if cmd.starts_with("BLOCK_POINT_PICKED ") => {
@@ -504,6 +562,7 @@ impl OpenCADStudio {
                 }
                 self.tabs[i].active_cmd = None;
                 self.active_modal = Some(crate::app::ModalKind::BlockDefinition);
+                self.refresh_block_definition_preview();
             }
 
             cmd if cmd.starts_with("WBLOCK_POINT_PICKED ") => {
diff --git a/src/app/control/actions.rs b/src/app/control/actions.rs
index 345ae4af0..ce75ab662 100644
--- a/src/app/control/actions.rs
+++ b/src/app/control/actions.rs
@@ -120,6 +120,7 @@ pub(super) const NAMES: &[&str] = &[
     "ribbon_dropdown",
     "keytips",
     "dialog_ok",
+    "block_def_dialog",
     "attdef_dialog",
     "field_dialog",
     "sheet_set",
@@ -1504,6 +1505,26 @@ impl OpenCADStudio {
                 }
                 return Ok(Task::none());
             }
+            // The open Block Definition dialog: `name=…`, `open_in_editor=0|1`,
+            // `base_on_screen=0|1`, `objects_on_screen=0|1`, `create_empty`,
+            // `select_objects`.
+            "block_def_dialog" => {
+                if self.block_definition.is_none() {
+                    return Err(failure("no_dialog", "The Block Definition dialog is not open"));
+                }
+                let value = string(req, "value")?;
+                let (key, v) = value.split_once('=').unwrap_or((value, ""));
+                let on = v == "1";
+                match key {
+                    "name" => Message::BlockDefNameSelect(v.to_string()),
+                    "open_in_editor" => Message::BlockDefOpenInEditor(on),
+                    "base_on_screen" => Message::BlockDefBaseOnScreen(on),
+                    "objects_on_screen" => Message::BlockDefObjectsOnScreen(on),
+                    "create_empty" => Message::BlockDefCreateEmpty,
+                    "select_objects" => Message::BlockDefSelectObjects,
+                    _ => return Err(failure("invalid_value", "Unknown block definition field")),
+                }
+            }
             // One field of the open attribute definition dialog: `tag=…`,
             // `prompt=…`, `default=…`, `justify=MC`, `style=…`, `height=…`,
             // `rotation=…`, `width=…`, `on_screen=0|1`, `x=…` / `y=…` / `z=…`,
diff --git a/src/app/mod.rs b/src/app/mod.rs
index 22ed7bf44..cbda679f2 100644
--- a/src/app/mod.rs
+++ b/src/app/mod.rs
@@ -581,6 +581,9 @@ pub(super) struct OpenCADStudio {
     drawing_units: Option<crate::ui::window::drawing_units::State>,
     /// Working copy of the Block Definition dialog; `None` while it is closed.
     block_definition: Option<crate::ui::window::block_definition::BlockDefinitionState>,
+    /// The block the Block Definition dialog defines with "Open in block
+    /// editor" on; it opens once the definition is committed.
+    block_definition_open_editor: Option<String>,
     block_edit_picker: Option<crate::ui::window::block_edit_picker::State>,
     block_save_as: Option<crate::ui::window::block_save_as::State>,
     /// PDF dialogs' working copies; `None` while closed.
@@ -3463,6 +3466,10 @@ pub enum Message {
     BlockDefConfirmRedefine(bool),
     BlockDefDismissError,
     BlockDefHelp,
+    /// Block Definition: open the new block in the block editor.
+    BlockDefOpenInEditor(bool),
+    /// Block Definition: define the block with no objects.
+    BlockDefCreateEmpty,
     /// Write Block (WBLOCK) dialog messages
     WblockSourceMode(crate::ui::window::wblock::WblockSourceMode),
     WblockBlockName(String),
@@ -4625,6 +4632,7 @@ impl OpenCADStudio {
             layer_translator: None,
             drawing_units: None,
             block_definition: None,
+            block_definition_open_editor: None,
             block_edit_picker: None,
             block_save_as: None,
             pdf_attach: None,
diff --git a/src/app/update/mod.rs b/src/app/update/mod.rs
index 0e2792ccd..24e279ede 100644
--- a/src/app/update/mod.rs
+++ b/src/app/update/mod.rs
@@ -5750,6 +5750,7 @@ impl OpenCADStudio {
                     state.error_message = None;
                     state.confirm_redefine = None;
                 }
+                self.refresh_block_definition_preview();
                 Task::none()
             }
             Message::BlockDefNameSelect(chosen) => {
@@ -5765,6 +5766,7 @@ impl OpenCADStudio {
                     );
                     state.set_base_point(glam::DVec3::new(base.x, base.y, base.z));
                 }
+                self.refresh_block_definition_preview();
                 Task::none()
             }
             Message::BlockDefBaseOnScreen(val) => {
@@ -5886,6 +5888,12 @@ impl OpenCADStudio {
                 }
                 Task::none()
             }
+            Message::BlockDefOpenInEditor(on) => {
+                if let Some(state) = self.block_definition.as_mut() {
+                    state.open_in_editor = on;
+                }
+                Task::none()
+            }
             Message::BlockDefHelp => {
                 self.command_line.push_info(
                     crate::t!("BLOCK creates a block definition from objects you select.").as_ref(),
@@ -5901,7 +5909,8 @@ impl OpenCADStudio {
                 }
                 self.commit_block_definition(true)
             }
-            Message::BlockDefApply => {
+            m @ (Message::BlockDefApply | Message::BlockDefCreateEmpty) => {
+                let create_empty = matches!(m, Message::BlockDefCreateEmpty);
                 let Some(state) = self.block_definition.as_mut() else {
                     return Task::none();
                 };
@@ -5924,15 +5933,16 @@ impl OpenCADStudio {
                         Some(crate::t!("Block name cannot start with '*'.").into_owned());
                     return Task::none();
                 }
-                if !state.objects_specify_onscreen && state.selected_handles.is_empty() {
-                    state.error_message = Some(
-                        crate::t!(
-                            "No objects selected. You must select objects to define a block."
-                        )
-                        .into_owned(),
-                    );
+                // No objects: the band offers to select some or to define
+                // an empty block.
+                if !state.objects_specify_onscreen
+                    && state.selected_handles.is_empty()
+                    && !create_empty
+                {
+                    state.empty_prompt = true;
                     return Task::none();
                 }
+                state.empty_prompt = false;
                 let i = self.active_tab;
                 if self.tabs[i]
                     .scene
@@ -7459,6 +7469,7 @@ impl OpenCADStudio {
                         .collect();
                     block_def.error_message = None;
                     self.active_modal = Some(super::ModalKind::BlockDefinition);
+                    self.refresh_block_definition_preview();
                 } else if let Some(ref mut wblock) = self.wblock {
                     wblock.selected_handles = self.tabs[i]
                         .scene
diff --git a/src/app/view/modal.rs b/src/app/view/modal.rs
index cae7c00d6..a6c6a4e3d 100644
--- a/src/app/view/modal.rs
+++ b/src/app/view/modal.rs
@@ -506,7 +506,7 @@ impl OpenCADStudio {
             }
             super::super::ModalKind::BlockDefinition => {
                 let state = self.block_definition.as_ref()?;
-                sized_flow(ex, 580, 390, |flow| {
+                sized_flow(ex, 600, 560, |flow| {
                     crate::ui::window::block_definition::view_window(state, flow)
                 })
             }
diff --git a/src/locale_catalog.rs b/src/locale_catalog.rs
index 35ceea96d..d421411a5 100644
--- a/src/locale_catalog.rs
+++ b/src/locale_catalog.rs
@@ -3,6 +3,10 @@
 
 pub(super) fn message_attribute(source: &str) -> Option<(&'static str, &'static str)> {
     match source {
+        "Open in block editor after creating" => Some(("block-def-dialog", "open-in-editor")),
+        "Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time." => Some(("block-def-dialog", "remembered")),
+        "No objects are selected for the block." => Some(("block-def-dialog", "no-objects")),
+        "Create empty block" => Some(("block-def-dialog", "create-empty")),
         "{} entities added" => Some(("ref-edit", "entities-added")),
         "Use REFCLOSE or the Refedit toolbar to end reference editing session." => Some(("ref-edit", "use-refclose")),
         "Specify opposite corner:" => Some(("ref-edit", "opposite-corner")),
diff --git a/src/ui/window/block_definition.rs b/src/ui/window/block_definition.rs
index 8f76f5331..e500f96c0 100644
--- a/src/ui/window/block_definition.rs
+++ b/src/ui/window/block_definition.rs
@@ -11,6 +11,7 @@ use iced::widget::{
 use iced::{Background, Border, Element, Fill, Length, Theme};
 
 use crate::app::Message;
+use crate::scene::WireModel;
 use crate::modules::draw::units;
 use crate::t;
 use crate::ui::style::common::muted_style;
@@ -73,6 +74,14 @@ pub struct BlockDefinitionState {
     pub error_message: Option<String>,
     pub confirm_redefine: Option<String>,
     pub desc_placeholder: String,
+    /// The selected objects, or the chosen existing definition, as drawn in
+    /// the name card.
+    pub preview: Vec<WireModel>,
+    /// OK was pressed with no objects: the band offers to select some or to
+    /// define an empty block.
+    pub empty_prompt: bool,
+    /// Open the new block in the block editor once it is defined.
+    pub open_in_editor: bool,
 }
 
 impl Clone for BlockDefinitionState {
@@ -100,6 +109,9 @@ impl Clone for BlockDefinitionState {
             error_message: self.error_message.clone(),
             confirm_redefine: self.confirm_redefine.clone(),
             desc_placeholder: self.desc_placeholder.clone(),
+            preview: self.preview.clone(),
+            empty_prompt: self.empty_prompt,
+            open_in_editor: self.open_in_editor,
         }
     }
 }
@@ -132,6 +144,9 @@ impl BlockDefinitionState {
             error_message: None,
             confirm_redefine: None,
             desc_placeholder: crate::t!("Enter block description...").into_owned(),
+            preview: Vec::new(),
+            empty_prompt: false,
+            open_in_editor: remembered.open_in_editor,
         }
     }
 
@@ -219,6 +234,45 @@ pub(crate) fn labeled_checkbox<'a>(
     .into()
 }
 
+/// The in-window warning shown when OK is pressed with no objects: select
+/// some, or define an empty block.
+fn empty_band<'a>() -> Element<'a, Message> {
+    container(
+        row![
+            crate::ui::icons::semantic(ICON_WARN, 15.0),
+            text(t!("No objects are selected for the block."))
+                .size(11)
+                .width(Fill),
+            button(text(t!("Select objects")).size(11))
+                .on_press(Message::BlockDefSelectObjects)
+                .style(button_style(false))
+                .padding([4, 12]),
+            button(text(t!("Create empty block")).size(11))
+                .on_press(Message::BlockDefCreateEmpty)
+                .style(button_style(false))
+                .padding([4, 12]),
+        ]
+        .spacing(10)
+        .align_y(iced::Center),
+    )
+    .padding([7, 10])
+    .width(Fill)
+    .style(|_: &Theme| {
+        // Amber: the theme's warning colour is not a caution tone in every theme.
+        let warn = iced::Color::from_rgb8(0xD9, 0xA4, 0x00);
+        container::Style {
+            background: Some(Background::Color(warn.scale_alpha(0.16))),
+            border: Border {
+                width: 1.0,
+                radius: 6.0.into(),
+                color: warn,
+            },
+            ..Default::default()
+        }
+    })
+    .into()
+}
+
 pub fn view_window<'a>(
     state: &'a BlockDefinitionState,
     sizing: crate::ui::modal::ModalSizing,
@@ -274,7 +328,21 @@ pub fn view_window<'a>(
         name_column = name_column.push(hint);
     }
 
-    let name_section = name_column;
+    // The name card carries a live preview of the selected objects, or of
+    // the existing definition the name picks.
+    let preview = container(super::block_palette::preview_canvas(&state.preview, 86.0))
+        .padding(3)
+        .width(Length::Fixed(150.0))
+        .height(Length::Fixed(92.0))
+        .style(crate::ui::window::pdf_dialogs::well_style);
+    let name_section = container(
+        row![name_column, preview]
+            .spacing(12)
+            .align_y(iced::Center),
+    )
+    .padding([8, 10])
+    .width(Fill)
+    .style(crate::ui::window::pdf_dialogs::card_style);
 
     // ── Group: Base Point ─────────────────────────────────────────────────────
     let base_onscreen = labeled_checkbox(
@@ -587,16 +655,49 @@ pub fn view_window<'a>(
 
     // ── Footer Bar ────────────────────────────────────────────────────────────
     let actions = row![
+        button(text("?").size(12))
+            .on_press(Message::BlockDefHelp)
+            .style(button_style(false))
+            .padding([3, 10]),
         Space::new().width(Fill),
-        dialog_button(t!("OK"), Message::BlockDefApply, true),
         dialog_button(t!("Cancel"), Message::CloseModal, false),
-        dialog_button(t!("Help"), Message::BlockDefHelp, false),
+        dialog_button(t!("OK"), Message::BlockDefApply, true),
     ]
     .spacing(8)
     .align_y(iced::Center);
 
+    // ── Open in the block editor ─────────────────────────────────────────────
+    let editor_card = container(
+        column![
+            row![
+                iced::widget::toggler(state.open_in_editor)
+                    .on_toggle(Message::BlockDefOpenInEditor)
+                    .size(16.0),
+                text(t!("Open in block editor after creating")).size(11),
+            ]
+            .spacing(8)
+            .align_y(iced::Center),
+            text(t!(
+                "Specify On-screen, the object option, Allow exploding and this switch are remembered for the next time."
+            ))
+            .size(10)
+            .style(muted_style),
+        ]
+        .spacing(4),
+    )
+    .padding([8, 10])
+    .width(Fill)
+    .style(crate::ui::window::pdf_dialogs::card_style);
+
     // ── Error Banner ──────────────────────────────────────────────────────────
-    let mut main_column = column![name_section, main_body, actions,]
+    let mut main_column = column![name_section];
+    if state.empty_prompt {
+        main_column = main_column.push(empty_band());
+    }
+    let mut main_column = main_column
+        .push(main_body)
+        .push(editor_card)
+        .push(actions)
         .spacing(6)
         .padding([8, 10])
         .width(sizing.width);