diff --git a/shared/src/main/scala/com/mogproject/mogami/core/State.scala b/shared/src/main/scala/com/mogproject/mogami/core/State.scala
index 4ae5030..f980b8b 100644
--- a/shared/src/main/scala/com/mogproject/mogami/core/State.scala
+++ b/shared/src/main/scala/com/mogproject/mogami/core/State.scala
@@ -257,6 +257,10 @@ case class State(turn: Player = BLACK, board: BoardType = Map.empty, hand: HandT
     case None => List()
   }
 
+  /**
+    * Check if the in-hand piece is non-empty.
+    */
+  def hasHand(h: Hand): Boolean = hand.get(h).exists(_ > 0)
 }
 
 object State extends CsaStateReader with SfenStateReader {
diff --git a/shared/src/test/scala/com/mogproject/mogami/core/StateSpec.scala b/shared/src/test/scala/com/mogproject/mogami/core/StateSpec.scala
index 77b1549..fa909ed 100644
--- a/shared/src/test/scala/com/mogproject/mogami/core/StateSpec.scala
+++ b/shared/src/test/scala/com/mogproject/mogami/core/StateSpec.scala
@@ -882,4 +882,11 @@ class StateSpec extends FlatSpec with MustMatchers with GeneratorDrivenPropertyC
         |P-00HI00KA00KI00GI00KE00KY00FU
         |-""".stripMargin).get.isMated mustBe false
   }
+
+  "State#hasHand" must "return if the in-hand piece exists" in {
+    State.HIRATE.hasHand(Hand(BP)) mustBe false
+    State.empty.updateHandPiece(BP, 1).get.hasHand(Hand(BP)) mustBe true
+    State.empty.updateHandPiece(BP, 2).get.hasHand(Hand(BP)) mustBe true
+    State.empty.updateHandPiece(BP, 18).get.hasHand(Hand(BP)) mustBe true
+  }
 }
\ No newline at end of file