diff --git a/src/game.rs b/src/game.rs
index 1f09fba..9316227 100644
--- a/src/game.rs
+++ b/src/game.rs
@@ -156,6 +156,11 @@ impl Game {
                     player_hand.push(self.deal());
                 }
                 PlayerChoice::DoubleDown => {
+                    if player_hand.cards().len() >= 3 {
+                        // Can only double-down as first move
+                        // TODO: Provide feedback that this move is invalid
+                        continue;
+                    }
                     if *money_on_table >= bet_amount {
                         *money_on_table -= bet_amount;
                         bet_amount *= 2;
diff --git a/src/main.rs b/src/main.rs
index fb2b4c2..5a61da0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -115,18 +115,27 @@ fn interactive_decision(hand: &Hand, dealer_showing: &Card) -> PlayerChoice {
 
 fn basic_strategy(hand: &Hand, dealer_showing: &Card) -> PlayerChoice {
     // Source: https://en.wikipedia.org/wiki/Blackjack#Basic_strategy
-    // TODO: Add doubling when it's supported
     let dv = u8::from(dealer_showing);
+    let can_dd = hand.cards().len() == 2;
     if hand.has_ace() && hand.cards().len() == 2 {
         // Ace and some other card
         match hand.value() {
             v if v >= 19 => PlayerChoice::Stand,
             v if v == 18 && (7..=8).contains(&dv) => PlayerChoice::Stand,
-            v if v == 18 && dv < 7 => PlayerChoice::DoubleDown,
-            v if v == 17 && (3..=6).contains(&dv) => PlayerChoice::DoubleDown,
-            v if (15..=16).contains(&v) && (4..=6).contains(&dv) => PlayerChoice::DoubleDown,
-            v if (13..=14).contains(&v) && (5..=6).contains(&dv) => PlayerChoice::DoubleDown,
-            v if v == 12 && dv == 6 => PlayerChoice::DoubleDown,
+            v if v == 18 && dv < 7 && can_dd => PlayerChoice::DoubleDown,
+            v if v == 18 && dv < 7 => PlayerChoice::Stand,
+            v if v == 17 && (3..=6).contains(&dv) && can_dd => PlayerChoice::DoubleDown,
+            v if v == 17 && (3..=6).contains(&dv) => PlayerChoice::Hit,
+            v if (15..=16).contains(&v) && (4..=6).contains(&dv) && can_dd => {
+                PlayerChoice::DoubleDown
+            }
+            v if (15..=16).contains(&v) && (4..=6).contains(&dv) => PlayerChoice::Hit,
+            v if (13..=14).contains(&v) && (5..=6).contains(&dv) && can_dd => {
+                PlayerChoice::DoubleDown
+            }
+            v if (13..=14).contains(&v) && (5..=6).contains(&dv) => PlayerChoice::Hit,
+            v if v == 12 && dv == 6 && can_dd => PlayerChoice::DoubleDown,
+            v if v == 12 && dv == 6 => PlayerChoice::Hit,
             _ => PlayerChoice::Hit,
         }
     } else {
@@ -134,9 +143,12 @@ fn basic_strategy(hand: &Hand, dealer_showing: &Card) -> PlayerChoice {
             v if v >= 17 => PlayerChoice::Stand,
             v if v > 12 && dv < 7 => PlayerChoice::Stand,
             v if v == 12 && (4..=6).contains(&dv) => PlayerChoice::Stand,
-            v if v == 11 => PlayerChoice::DoubleDown,
-            v if v == 10 && dv < 10 => PlayerChoice::DoubleDown,
-            v if v == 9 && (3..=6).contains(&dv) => PlayerChoice::DoubleDown,
+            v if v == 11 && can_dd => PlayerChoice::DoubleDown,
+            v if v == 11 => PlayerChoice::Hit,
+            v if v == 10 && dv < 10 && can_dd => PlayerChoice::DoubleDown,
+            v if v == 10 && dv < 10 => PlayerChoice::Hit,
+            v if v == 9 && (3..=6).contains(&dv) && can_dd => PlayerChoice::DoubleDown,
+            v if v == 9 && (3..=6).contains(&dv) => PlayerChoice::Hit,
             _ => PlayerChoice::Hit,
         }
     }