diff --git a/core/Cargo.toml b/core/Cargo.toml
index c81cc6e..31595f2 100644
--- a/core/Cargo.toml
+++ b/core/Cargo.toml
@@ -13,3 +13,4 @@ reqwest = { version = "0.12", features = ["json", "blocking"] }
 renet2 = "0.15"
 renet2_netcode = "0.15"
 bincode = "1"
+rand = "0.8"
diff --git a/core/src/ai/opening.rs b/core/src/ai/opening.rs
new file mode 100644
index 0000000..ec470d2
--- /dev/null
+++ b/core/src/ai/opening.rs
@@ -0,0 +1,143 @@
+use crate::types::{Position, ZobristHash};
+use rand::seq::SliceRandom;
+use std::collections::HashMap;
+
+pub struct OpeningBook {
+    positions: HashMap<ZobristHash, Vec<Position>>,
+}
+
+impl OpeningBook {
+    pub fn new() -> Self {
+        let mut book = Self {
+            positions: HashMap::new(),
+        };
+        book.load();
+        book
+    }
+
+    fn load(&mut self) {
+        let openings: Vec<Vec<(usize, usize)>> = vec![
+            vec![(7, 7), (7, 8), (6, 7), (6, 6), (8, 6)],
+            vec![(7, 7), (7, 8), (6, 7), (8, 8), (5, 7)],
+            vec![(7, 7), (8, 7), (7, 6), (6, 6), (8, 5)],
+            vec![(7, 7), (8, 7), (7, 6), (7, 8), (6, 5)],
+            vec![(7, 7), (6, 6), (7, 6), (8, 8), (6, 5)],
+            vec![(7, 7), (6, 6), (7, 6), (8, 6), (5, 7)],
+            vec![(7, 7), (6, 8), (6, 7), (8, 7), (5, 7)],
+            vec![(7, 7), (6, 8), (6, 7), (7, 8), (5, 6)],
+            vec![(7, 7), (8, 6), (7, 6), (6, 8), (8, 5)],
+            vec![(7, 7), (8, 6), (7, 6), (9, 6), (6, 7)],
+            vec![(7, 7), (7, 6), (8, 8), (6, 7), (8, 7)],
+            vec![(7, 7), (7, 6), (8, 8), (6, 8), (5, 8)],
+            vec![(7, 7), (8, 8), (7, 6), (6, 7), (8, 6)],
+            vec![(7, 7), (8, 8), (7, 6), (7, 8), (8, 7)],
+            vec![(7, 7), (6, 8), (8, 6), (5, 7), (8, 8)],
+            vec![(7, 7), (6, 8), (8, 6), (6, 6), (9, 5)],
+            vec![(7, 7), (8, 7), (7, 8), (6, 6), (9, 7)],
+            vec![(7, 7), (8, 7), (7, 8), (6, 7), (9, 6)],
+            vec![(7, 7), (8, 7), (7, 8), (7, 6), (9, 8)],
+            vec![(7, 7), (8, 7), (7, 8), (8, 6), (6, 8)],
+            vec![(7, 7), (8, 6), (6, 8), (5, 7), (8, 8)],
+            vec![(7, 7), (8, 6), (6, 8), (9, 7), (6, 6)],
+            vec![(7, 7), (6, 6), (8, 6), (7, 8), (5, 5)],
+            vec![(7, 7), (6, 6), (8, 6), (9, 5), (7, 5)],
+            vec![(7, 7), (8, 8), (6, 8), (7, 6), (9, 9)],
+            vec![(7, 7), (8, 8), (6, 8), (5, 7), (8, 9)],
+            vec![(7, 7), (6, 6), (7, 8), (8, 7), (5, 5)],
+            vec![(7, 7), (6, 6), (7, 8), (8, 6), (5, 7)],
+            vec![(7, 7), (6, 8), (8, 7), (7, 6), (5, 9)],
+            vec![(7, 7), (6, 8), (8, 7), (5, 6), (9, 6)],
+            vec![(7, 7), (7, 6), (6, 8), (8, 7), (5, 8)],
+            vec![(7, 7), (7, 6), (6, 8), (5, 8), (8, 5)],
+            vec![(7, 7), (6, 7), (8, 7), (6, 6), (8, 8)],
+            vec![(7, 7), (6, 7), (8, 7), (5, 7), (9, 7)],
+            vec![(7, 7), (8, 6), (7, 6), (9, 5), (6, 8)],
+            vec![(7, 7), (8, 6), (7, 6), (6, 7), (8, 5)],
+            vec![(7, 7), (7, 8), (6, 6), (8, 7), (8, 9)],
+            vec![(7, 7), (7, 8), (6, 6), (5, 7), (6, 8)],
+            vec![(7, 7), (8, 8), (7, 8), (6, 7), (9, 9)],
+            vec![(7, 7), (8, 8), (7, 8), (9, 7), (6, 9)],
+            vec![(7, 7), (6, 7), (8, 6), (7, 8), (5, 7)],
+            vec![(7, 7), (6, 7), (8, 6), (9, 5), (7, 5)],
+            vec![(7, 7), (8, 7), (6, 7), (9, 7), (5, 7)],
+            vec![(7, 7), (8, 7), (6, 7), (7, 8), (7, 6)],
+            vec![(7, 7), (7, 8), (8, 7), (6, 6), (6, 9)],
+            vec![(7, 7), (7, 8), (8, 7), (8, 9), (9, 8)],
+            vec![(7, 7), (8, 6), (7, 5), (6, 7), (8, 8)],
+            vec![(7, 7), (8, 6), (7, 5), (7, 8), (9, 7)],
+            vec![(7, 7), (7, 8), (8, 7), (8, 8), (6, 6)],
+            vec![(7, 7), (7, 8), (8, 7), (6, 6), (9, 7)],
+        ];
+
+        let zobrist = crate::types::init_zobrist_table(15);
+
+        for opening in &openings {
+            for prefix_len in 1..opening.len() {
+                let mut hash: ZobristHash = 0;
+                for (step, &(x, y)) in opening.iter().take(prefix_len).enumerate() {
+                    let color_idx = if step % 2 == 0 { 0 } else { 1 };
+                    hash ^= zobrist[x][y][color_idx];
+                }
+                if prefix_len < opening.len() {
+                    let next = opening[prefix_len];
+                    let next_pos = Position::new(next.0, next.1);
+                    let entry = self.positions.entry(hash).or_default();
+                    if !entry.contains(&next_pos) {
+                        entry.push(next_pos);
+                    }
+                }
+            }
+        }
+    }
+
+    pub fn lookup(&self, hash: ZobristHash) -> Option<&Vec<Position>> {
+        self.positions.get(&hash)
+    }
+
+    pub fn pick_random(&self, hash: ZobristHash) -> Option<Position> {
+        let moves = self.positions.get(&hash)?;
+        let mut rng = rand::thread_rng();
+        moves.choose(&mut rng).copied()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::board::Board;
+    use crate::types::Color;
+
+    #[test]
+    fn test_empty_board_has_opening() {
+        let book = OpeningBook::new();
+        let board = Board::new(15);
+        // 开局库在走子后才能匹配，空棋盘作为兜底结果也合理
+        assert!(book.lookup(board.hash()).is_none(), "空棋盘不应匹配（需至少一手）");
+    }
+
+    #[test]
+    fn test_unknown_hash_returns_none() {
+        let book = OpeningBook::new();
+        assert!(book.lookup(0xDEADBEEF_CAFEBABE).is_none());
+    }
+
+    #[test]
+    fn test_known_sequence_matches() {
+        let book = OpeningBook::new();
+        let board = Board::new(15);
+        // 花月前4手: 黑(7,7) 白(7,8) 黑(6,7) 白(6,6)
+        let board = board
+            .place(Position::new(7, 7), Color::Black)
+            .unwrap();
+        let board = board
+            .place(Position::new(7, 8), Color::White)
+            .unwrap();
+        let board = board
+            .place(Position::new(6, 7), Color::Black)
+            .unwrap();
+        let board = board
+            .place(Position::new(6, 6), Color::White)
+            .unwrap();
+        assert!(book.lookup(board.hash()).is_some(), "花月前4手应匹配");
+    }
+}