diff --git a/petri/src/lib.rs b/petri/src/lib.rs
index 63f5501..686c795 100644
--- a/petri/src/lib.rs
+++ b/petri/src/lib.rs
@@ -18,8 +18,10 @@ pub struct Chunk {
 	pub contents: Box<[[Cell; CHUNK_SIZE]; CHUNK_SIZE]>,
 }
 
-#[derive(Debug, Default, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct Rule {
+	#[serde(default)]
+	pub name: String,
 	base: SubRule,
 	#[serde(skip)]
 	variants: Vec<SubRule>,
@@ -61,12 +63,6 @@ pub enum RuleCellTo {
 	Copy(usize),
 }
 
-impl std::default::Default for SubRule {
-	fn default() -> Self {
-		Self::new()
-	}
-}
-
 impl SubRule {
 	fn new() -> Self {
 		Self {
@@ -119,6 +115,18 @@ impl Rule {
 	pub const SHRINK_UP: ResizeParam = (0, -1, 0, 1);
 	pub const SHRINK_DOWN: ResizeParam = (0, -1, 0, 0);
 
+	pub fn new() -> Self {
+		Self {
+			name: "new rule".into(),
+			enabled: false,
+			base: SubRule::new(),
+			variants: vec![SubRule::new()],
+			flip_h: false,
+			flip_v: false,
+			rotate: false,
+		}
+	}
+
 	pub fn get(&self, x: usize, y: usize) -> (RuleCellFrom, RuleCellTo) {
 		self.base.get(x, y)
 	}
@@ -280,7 +288,7 @@ impl Dish {
 						(RuleCellFrom::One(Cell(0)), RuleCellTo::One(Cell(1))),
 					],
 				},
-				..Rule::default()
+				..Rule::new()
 			},
 			Rule {
 				enabled: true,
@@ -295,7 +303,7 @@ impl Dish {
 					],
 				},
 				flip_h: true,
-				..Rule::default()
+				..Rule::new()
 			},
 		];
 
diff --git a/uscope/src/main.rs b/uscope/src/main.rs
index f36c2b6..1b47900 100644
--- a/uscope/src/main.rs
+++ b/uscope/src/main.rs
@@ -174,19 +174,30 @@ impl eframe::App for UScope {
 					ui.heading("Rules");
 
 					let mut to_remove = None;
+					let mut to_clone = None;
 					for (i, rule) in self.dish.rules.iter_mut().enumerate() {
 						ui.separator();
 						rule_editor(ui, rule, &self.cell_types, &self.dish.cell_groups);
-						if ui.button("delete").clicked() {
-							to_remove = Some(i);
-						}
+						ui.horizontal(|ui| {
+							if ui.button("delete").clicked() {
+								to_remove = Some(i);
+							}
+							if ui.button("copy").clicked() {
+								to_clone = Some(i);
+							}
+						});
 					}
 					if let Some(i) = to_remove {
 						self.dish.rules.remove(i);
 					}
+					if let Some(i) = to_clone {
+						let mut new_rule = self.dish.rules[i].clone();
+						new_rule.enabled = false;
+						self.dish.rules.push(new_rule);
+					}
 					ui.separator();
 					if ui.button("add rule").clicked() {
-						self.dish.rules.push(Rule::default());
+						self.dish.rules.push(Rule::new());
 					}
 				});
 			});