diff --git a/crates/engine/src/cmd/style.rs b/crates/engine/src/cmd/style.rs
index 38eb20d23..7559a8179 100644
--- a/crates/engine/src/cmd/style.rs
+++ b/crates/engine/src/cmd/style.rs
@@ -511,12 +511,29 @@ fn edit_para(s: &mut Session, p: &Value) -> Result<Value> {
 
 /// Rename a paragraph or character style everywhere it's used.
 fn rename_style(d: &mut designcraft_doc::Document, para: bool, from: &str, to: &str) {
-    let st = d.styles_mut();
     if para {
-        for s in &mut st.paragraph {
+        for s in &mut d.styles_mut().paragraph {
             if s.name == from {
                 s.name = to.to_string();
             }
+        }
+    } else {
+        for s in &mut d.styles_mut().character {
+            if s.name == from {
+                s.name = to.to_string();
+            }
+        }
+    }
+    redirect_style_refs(d, para, from, to);
+}
+
+/// Point every reference to style `from` at `to`, except the style's own registry entry (its
+/// `name` field) — shared by renaming (which also updates the entry's name) and deletion (which
+/// instead removes the entry, after its former uses point at the replacement).
+fn redirect_style_refs(d: &mut designcraft_doc::Document, para: bool, from: &str, to: &str) {
+    let st = d.styles_mut();
+    if para {
+        for s in &mut st.paragraph {
             for r in [&mut s.based_on, &mut s.next_style] {
                 if r.as_deref() == Some(from) {
                     *r = Some(to.to_string());
@@ -530,9 +547,6 @@ fn rename_style(d: &mut designcraft_doc::Document, para: bool, from: &str, to: &
         }
     } else {
         for s in &mut st.character {
-            if s.name == from {
-                s.name = to.to_string();
-            }
             if s.based_on.as_deref() == Some(from) {
                 s.based_on = Some(to.to_string());
             }
@@ -564,7 +578,8 @@ fn rename_style(d: &mut designcraft_doc::Document, para: bool, from: &str, to: &
     }
 }
 
-/// Point the nested, nested line and GREP styles of paragraph attributes at a renamed character style.
+/// Point the nested, nested line and GREP styles, and the drop cap style, of paragraph
+/// attributes at a renamed (or deleted, pointed at its replacement) character style.
 fn rename_char_refs(p: &mut ParaAttrs, from: &str, to: &str) {
     let names = p.nested_styles.iter_mut().flatten().map(|n| &mut n.style);
     let names = names.chain(p.nested_line_styles.iter_mut().flatten().map(|n| &mut n.style));
@@ -573,6 +588,9 @@ fn rename_char_refs(p: &mut ParaAttrs, from: &str, to: &str) {
             *n = to.to_string();
         }
     }
+    if p.drop_cap_style.as_deref() == Some(from) {
+        p.drop_cap_style = Some(to.to_string());
+    }
 }
 
 fn group_styles(s: &mut Session, p: &Value) -> Result<Value> {
@@ -610,22 +628,23 @@ fn group_styles(s: &mut Session, p: &Value) -> Result<Value> {
 }
 
 fn delete_para(s: &mut Session, p: &Value) -> Result<Value> {
-    let name = str_param(p, "name").unwrap_or("").to_string();
+    let name = str_param(p, "name").filter(|n| !n.is_empty()).ok_or_else(|| bad("style.paragraph.delete", "missing name"))?.to_string();
     let repl = str_param(p, "replaceWith").unwrap_or(designcraft_doc::BASIC_PARAGRAPH).to_string();
     if name.starts_with('[') {
         return Err(bad("style.paragraph.delete", "built-in styles can't be deleted"));
     }
+    if repl == name {
+        return Err(bad("style.paragraph.delete", "`replaceWith` can't be the deleted style"));
+    }
     s.edit(|d, _| {
-        d.styles_mut().paragraph.retain(|x| x.name != name);
-        for sid in d.stories.keys().copied().collect::<Vec<_>>() {
-            if let Some(story) = d.story_mut(sid) {
-                for f in &mut story.paras {
-                    if f.style == name {
-                        f.style = repl.clone();
-                    }
-                }
-            }
+        if d.styles.para(&name).is_none() {
+            return Err(bad("style.paragraph.delete", format!("no paragraph style `{name}`")));
         }
+        if d.styles.para(&repl).is_none() {
+            return Err(bad("style.paragraph.delete", format!("no paragraph style `{repl}`")));
+        }
+        redirect_style_refs(d, true, &name, &repl);
+        d.styles_mut().paragraph.retain(|x| x.name != name);
         ok()
     })
 }
@@ -718,22 +737,23 @@ fn edit_char(s: &mut Session, p: &Value) -> Result<Value> {
 }
 
 fn delete_char(s: &mut Session, p: &Value) -> Result<Value> {
-    let name = str_param(p, "name").unwrap_or("").to_string();
+    let name = str_param(p, "name").filter(|n| !n.is_empty()).ok_or_else(|| bad("style.character.delete", "missing name"))?.to_string();
     let repl = str_param(p, "replaceWith").unwrap_or(designcraft_doc::NO_CHAR_STYLE).to_string();
     if name.starts_with('[') {
         return Err(bad("style.character.delete", "built-in styles can't be deleted"));
     }
+    if repl == name {
+        return Err(bad("style.character.delete", "`replaceWith` can't be the deleted style"));
+    }
     s.edit(|d, _| {
-        d.styles_mut().character.retain(|x| x.name != name);
-        for sid in d.stories.keys().copied().collect::<Vec<_>>() {
-            if let Some(story) = d.story_mut(sid) {
-                story.for_each_text_mut(&mut |st| {
-                    for r in st.chars.iter_mut().filter(|r| r.format.style == name) {
-                        r.format.style = repl.clone();
-                    }
-                });
-            }
+        if d.styles.char_style(&name).is_none() {
+            return Err(bad("style.character.delete", format!("no character style `{name}`")));
         }
+        if d.styles.char_style(&repl).is_none() {
+            return Err(bad("style.character.delete", format!("no character style `{repl}`")));
+        }
+        redirect_style_refs(d, false, &name, &repl);
+        d.styles_mut().character.retain(|x| x.name != name);
         ok()
     })
 }
diff --git a/crates/engine/src/tests.rs b/crates/engine/src/tests.rs
index e47542518..d7dc80b68 100644
--- a/crates/engine/src/tests.rs
+++ b/crates/engine/src/tests.rs
@@ -681,6 +681,56 @@ fn character_style_delete_rejects_builtin_styles() {
     assert!(r.is_err(), "built-in styles can't be deleted");
 }
 
+#[test]
+fn character_style_delete_rejects_missing_unknown_and_self_replacement() {
+    let mut s = session();
+    let name = s.execute("style.character.create", &json!({"name": "Key Term"})).unwrap()["name"].as_str().unwrap().to_string();
+    assert!(s.execute("style.character.delete", &json!({"name": ""})).is_err(), "empty name is rejected");
+    assert!(s.execute("style.character.delete", &json!({"name": "No Such Style"})).is_err(), "unknown name is rejected");
+    assert!(s.execute("style.character.delete", &json!({"name": name, "replaceWith": "No Such Style"})).is_err(), "unknown replaceWith is rejected");
+    assert!(s.execute("style.character.delete", &json!({"name": name, "replaceWith": name})).is_err(), "replaceWith can't be the deleted style");
+}
+
+#[test]
+fn paragraph_style_delete_rejects_missing_unknown_and_self_replacement() {
+    let mut s = session();
+    let name = s.execute("style.paragraph.create", &json!({"name": "Caption"})).unwrap()["name"].as_str().unwrap().to_string();
+    assert!(s.execute("style.paragraph.delete", &json!({"name": ""})).is_err(), "empty name is rejected");
+    assert!(s.execute("style.paragraph.delete", &json!({"name": "No Such Style"})).is_err(), "unknown name is rejected");
+    assert!(s.execute("style.paragraph.delete", &json!({"name": name, "replaceWith": "No Such Style"})).is_err(), "unknown replaceWith is rejected");
+    assert!(s.execute("style.paragraph.delete", &json!({"name": name, "replaceWith": name})).is_err(), "replaceWith can't be the deleted style");
+}
+
+#[test]
+fn character_style_delete_reassigns_every_kind_of_reference() {
+    let mut s = session();
+    let name = s.execute("style.character.create", &json!({"name": "Key Term"})).unwrap()["name"].as_str().unwrap().to_string();
+    let repl = s.execute("style.character.create", &json!({"name": "Emphasis"})).unwrap()["name"].as_str().unwrap().to_string();
+    // Another character style's basedOn.
+    let based = s.execute("style.character.create", &json!({"name": "Strong", "basedOn": name})).unwrap()["name"].as_str().unwrap().to_string();
+    // A paragraph style's nested, nested line, GREP and drop cap styles, and the footnote reference style.
+    s.execute(
+        "style.paragraph.create",
+        &json!({"name": "Body", "para": {
+            "nestedStyles": [{"style": name, "through": true, "count": 1, "until": {"kind": "words"}}],
+            "grepStyles": [{"style": name, "pattern": "x"}],
+            "nestedLineStyles": [{"style": name, "lines": 1}],
+            "dropCapStyle": name}}),
+    )
+    .unwrap();
+    s.execute("footnote.options", &json!({"refCharStyle": name})).unwrap();
+    s.execute("style.character.delete", &json!({"name": name, "replaceWith": repl})).unwrap();
+    let st = s.doc().unwrap();
+    assert!(st.doc.styles.char_style(&name).is_none(), "deleted style is gone");
+    assert_eq!(st.doc.styles.char_style(&based).unwrap().based_on.as_deref(), Some(repl.as_str()), "basedOn redirected");
+    let body = st.doc.styles.para("Body").unwrap();
+    assert_eq!(body.para.nested_styles.as_ref().unwrap()[0].style, repl, "nested style redirected");
+    assert_eq!(body.para.nested_line_styles.as_ref().unwrap()[0].style, repl, "nested line style redirected");
+    assert_eq!(body.para.grep_styles.as_ref().unwrap()[0].style, repl, "grep style redirected");
+    assert_eq!(body.para.drop_cap_style.as_deref(), Some(repl.as_str()), "drop cap style redirected");
+    assert_eq!(st.doc.footnote_options.ref_char_style, repl, "footnote reference style redirected");
+}
+
 #[test]
 fn page_tool_selects_a_page_and_its_handles_preview_or_resize_it() {
     use designcraft_tools::{CanvasLayout, Mods, PointerEvent, PointerKind};