diff --git a/src/grid.rs b/src/grid.rs
index 03e6c92..4954960 100644
--- a/src/grid.rs
+++ b/src/grid.rs
@@ -1,3 +1,5 @@
+mod rand;
+
 #[derive(Clone, Default, Debug, PartialEq)]
 pub enum Cell {
     /// Filled.
diff --git a/src/grid/rand.rs b/src/grid/rand.rs
new file mode 100644
index 0000000..23bd419
--- /dev/null
+++ b/src/grid/rand.rs
@@ -0,0 +1,14 @@
+use crate::grid::Cell;
+use rand::distributions::{Distribution, Standard};
+use rand::Rng;
+
+impl Distribution<Cell> for Standard {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> Cell {
+        let filled = rng.gen_bool(2. / 3.);
+        if filled {
+            Cell::Filled
+        } else {
+            Cell::Empty
+        }
+    }
+}