Fix decimal point case

.Lib9c.Tests/Action/HitHelperTest.cs

@@ -0,0 +1,34 @@
+namespace Lib9c.Tests.Action
+{
+    using System;
+    using Nekoyume.Battle;
+    using Xunit;
+
+    public class HitHelperTest
+    {
+        [Fact]
+        public void GetHitStep2()
+        {
+            // copy from previous logic
+            int GetHitStep2Legacy(int attackerHit, int defenderHit)
+            {
+                attackerHit = Math.Max(1, attackerHit);
+                defenderHit = Math.Max(1, defenderHit);
+                var additionalCorrection = (int)((attackerHit - defenderHit / 3m) / defenderHit * 100);
+                return Math.Min(
+                    Math.Max(additionalCorrection, HitHelper.GetHitStep2AdditionalCorrectionMin),
+                    HitHelper.GetHitStep2AdditionalCorrectionMax);
+            }
+
+            for (int i = 0; i < 9; i++)
+            {
+                for (int j = 0; j < 9; j++)
+                {
+                    var legacy = GetHitStep2Legacy(i, j);
+                    var current = HitHelper.GetHitStep2(i, j);
+                    Assert.True(legacy == current, $"{i}, {j}, {legacy}, {current}");
+                }
+            }
+        }
+    }
+}

Lib9c/Battle/HitHelper.cs

@@ -109,7 +109,7 @@ public static int GetHitStep2(int attackerHit, int defenderHit)
         {
             attackerHit = Math.Max(1, attackerHit);
             defenderHit = Math.Max(1, defenderHit);
-            var additionalCorrection = (attackerHit * 100 - defenderHit * 100 / 3) / defenderHit;
+            var additionalCorrection = (attackerHit * 10000 - defenderHit * 10000 / 3) / defenderHit / 100;
             return Math.Min(Math.Max(additionalCorrection, GetHitStep2AdditionalCorrectionMin),
                 GetHitStep2AdditionalCorrectionMax);
         }