diff --git a/src/node/node_modifier.rs b/src/node/node_modifier.rs
new file mode 100644
index 0000000..fb4b449
--- /dev/null
+++ b/src/node/node_modifier.rs
@@ -0,0 +1,24 @@
+use crate::node::Node;
+use rand::random_range;
+
+const PICK_STOP_PROBABILITY: u8 = 2;
+
+pub struct NodeModifier<'a> {
+    picked_node: &'a mut Node,
+}
+
+impl<'a> NodeModifier<'a> {
+    pub fn from_random(root: &'a mut Node) -> NodeModifier<'a> {
+        let mut selected = root;
+        while random_range(0..PICK_STOP_PROBABILITY) == PICK_STOP_PROBABILITY - 1 {
+            let len = selected.children.len();
+            selected = &mut selected.children[random_range(0..len)];
+        }
+        NodeModifier {
+            picked_node: selected,
+        }
+    }
+    pub fn from_node(node: &'a mut Node) -> NodeModifier<'a> {
+        NodeModifier { picked_node: node }
+    }
+}