diff --git a/CHANGELOG.md b/CHANGELOG.md
index 284d1b5d8..5d485c1fa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -38,6 +38,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed double-save bug in logout flow that caused unnecessary database operations
 - Fixed save operation ordering - now saves data before session cleanup instead of after
 - Fixed stale transmog/armor appearance shown to other players - user binary cache now invalidated when plate data is saved
+- Fixed server crash when Discord relay receives messages with unsupported Shift-JIS characters (emoji, Lenny faces, cuneiform, etc.)
 
 ### Security
 
diff --git a/common/stringsupport/string_convert.go b/common/stringsupport/string_convert.go
index 16627b2cc..2d09138f8 100644
--- a/common/stringsupport/string_convert.go
+++ b/common/stringsupport/string_convert.go
@@ -15,7 +15,15 @@ func UTF8ToSJIS(x string) []byte {
 	e := japanese.ShiftJIS.NewEncoder()
 	xt, _, err := transform.String(e, x)
 	if err != nil {
-		panic(err)
+		// Filter out runes that can't be encoded to Shift-JIS instead of
+		// crashing the server (see PR #116).
+		var filtered []rune
+		for _, r := range x {
+			if _, _, err := transform.String(japanese.ShiftJIS.NewEncoder(), string(r)); err == nil {
+				filtered = append(filtered, r)
+			}
+		}
+		xt, _, _ = transform.String(japanese.ShiftJIS.NewEncoder(), string(filtered))
 	}
 	return []byte(xt)
 }
@@ -36,9 +44,10 @@ func ToNGWord(x string) []uint16 {
 			t := UTF8ToSJIS(string(r))
 			if len(t) > 1 {
 				w = append(w, uint16(t[1])<<8|uint16(t[0]))
-			} else {
+			} else if len(t) == 1 {
 				w = append(w, uint16(t[0]))
 			}
+			// Skip runes that produced no SJIS output (unsupported characters)
 		} else {
 			w = append(w, uint16(r))
 		}
diff --git a/common/stringsupport/string_convert_test.go b/common/stringsupport/string_convert_test.go
index adfc434f4..69a93fdea 100644
--- a/common/stringsupport/string_convert_test.go
+++ b/common/stringsupport/string_convert_test.go
@@ -458,6 +458,80 @@ func BenchmarkCSVElems(b *testing.B) {
 	}
 }
 
+func TestUTF8ToSJIS_UnsupportedCharacters(t *testing.T) {
+	// Regression test for PR #116: Characters outside the Shift-JIS range
+	// (e.g. Lenny face, cuneiform) previously caused a panic in UTF8ToSJIS,
+	// crashing the server when relayed from Discord.
+	tests := []struct {
+		name  string
+		input string
+	}{
+		{"lenny_face", "( ͡° ͜ʖ ͡°)"},
+		{"cuneiform", "𒀜"},
+		{"emoji", "Hello 🎮 World"},
+		{"mixed_unsupported", "Test ͡° message 𒀜 here"},
+		{"zalgo_text", "H̷e̸l̵l̶o̷"},
+		{"only_unsupported", "🎮🎲🎯"},
+		{"cyrillic", "Привет"},
+		{"arabic", "مرحبا"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Must not panic - the old code would panic here
+			defer func() {
+				if r := recover(); r != nil {
+					t.Errorf("UTF8ToSJIS panicked on input %q: %v", tt.input, r)
+				}
+			}()
+			result := UTF8ToSJIS(tt.input)
+			if result == nil {
+				t.Error("UTF8ToSJIS returned nil")
+			}
+		})
+	}
+}
+
+func TestUTF8ToSJIS_PreservesValidContent(t *testing.T) {
+	// Verify that valid Shift-JIS content is preserved when mixed with
+	// unsupported characters.
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{"ascii_with_emoji", "Hello 🎮 World", "Hello  World"},
+		{"japanese_with_emoji", "テスト🎮データ", "テストデータ"},
+		{"only_valid", "Hello World", "Hello World"},
+		{"only_invalid", "🎮🎲🎯", ""},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sjis := UTF8ToSJIS(tt.input)
+			roundTripped := SJISToUTF8(sjis)
+			if roundTripped != tt.expected {
+				t.Errorf("UTF8ToSJIS(%q) round-tripped to %q, want %q", tt.input, roundTripped, tt.expected)
+			}
+		})
+	}
+}
+
+func TestToNGWord_UnsupportedCharacters(t *testing.T) {
+	// ToNGWord also calls UTF8ToSJIS internally, so it must not panic either.
+	inputs := []string{"( ͡° ͜ʖ ͡°)", "🎮", "Hello 🎮 World"}
+	for _, input := range inputs {
+		t.Run(input, func(t *testing.T) {
+			defer func() {
+				if r := recover(); r != nil {
+					t.Errorf("ToNGWord panicked on input %q: %v", input, r)
+				}
+			}()
+			_ = ToNGWord(input)
+		})
+	}
+}
+
 func BenchmarkUTF8ToSJIS(b *testing.B) {
 	text := "Hello World テスト"
 	b.ResetTimer()