diff --git a/src/modes/mod.rs b/src/modes/mod.rs
index 2fdacdc..4b38077 100644
--- a/src/modes/mod.rs
+++ b/src/modes/mod.rs
@@ -1 +1,13 @@
+mod pair;
 mod single;
+
+#[derive(Eq, Ord, PartialEq, PartialOrd, Debug, Copy, Clone)]
+pub enum Footstool {
+    None,
+    Half,
+    Full,
+}
+
+pub trait Hand {
+    fn footstool(&self, other: Self) -> Footstool;
+}