diff --git a/src/device/input/parse/v01/server.go b/src/device/input/parse/v01/server.go
index a861c5c..30b0312 100644
--- a/src/device/input/parse/v01/server.go
+++ b/src/device/input/parse/v01/server.go
@@ -205,13 +205,15 @@ func (v01 *V01) serveGMShuffle(w http.ResponseWriter, r *http.Request) {
 		poolSize = altSize
 	}
 	pool := make([]int, poolSize)
-	for i := range v01.cfg.Players {
-		pool[i] = i + 1
-	}
-	for i := 0; i < 30; i++ {
-		l := rand.Int() % poolSize
-		r := rand.Int() % poolSize
-		pool[l], pool[r] = pool[r], pool[l]
+	if poolSize > 0 {
+		for i := range v01.cfg.Players {
+			pool[i] = i + 1
+		}
+		for i := 0; i < 30; i++ {
+			l := rand.Int() % poolSize
+			r := rand.Int() % poolSize
+			pool[l], pool[r] = pool[r], pool[l]
+		}
 	}
 	i := 0
 	msg := []string{}
diff --git a/src/device/input/parse/v01/server_test.go b/src/device/input/parse/v01/server_test.go
index 3561bd6..35d4ddb 100644
--- a/src/device/input/parse/v01/server_test.go
+++ b/src/device/input/parse/v01/server_test.go
@@ -7,6 +7,7 @@ import (
 	"net/http/httptest"
 	"os"
 	"path"
+	"strconv"
 	"strings"
 	"sync"
 	"testing"
@@ -205,7 +206,7 @@ func TestServeGM(t *testing.T) {
 	})
 
 	t.Run("shuffle", func(t *testing.T) {
-		t.Run("2u 2p", func(t *testing.T) {
+		t.Run("many 2u 2p", func(t *testing.T) {
 			v01 := NewV01(ctx, nil)
 			for i := 0; i < 100; i++ {
 				v01.cfg.Quiet = true
@@ -231,6 +232,55 @@ func TestServeGM(t *testing.T) {
 				}
 			}
 		})
+
+		cases := map[string]struct {
+			users         int
+			usersAssigned int
+			players       int
+		}{
+			"empty": {},
+		}
+
+		for name, d := range cases {
+			c := d
+			t.Run(name, func(t *testing.T) {
+				v01 := NewV01(ctx, nil)
+				v01.cfg.Quiet = true
+				v01.cfg.Users = map[string]configUser{}
+				for i := 0; i < c.users; i++ {
+					v01.cfg.Users[strconv.Itoa(i)] = configUser{}
+					if i < c.usersAssigned {
+						v01.cfg.Users[strconv.Itoa(i)] = configUser{Player: i}
+					}
+				}
+				v01.cfg.Players = make([]configPlayer, c.players)
+
+				do(v01, "/gm/rpc/shuffle", "")
+				if v01.cfg.Quiet {
+					t.Error(v01.cfg.Quiet)
+				}
+
+				if len(v01.cfg.Users) != c.users+1 {
+					t.Error(v01.cfg.Users)
+				} else if len(v01.cfg.Players) != c.players {
+					t.Error(v01.cfg.Users)
+				}
+				for i := 0; i < c.users; i++ {
+					if _, ok := v01.cfg.Users[strconv.Itoa(i)]; !ok {
+						t.Error(i)
+					}
+				}
+				assignments := map[int]struct{}{}
+				for _, v := range v01.cfg.Users {
+					if v.Player > 0 {
+						assignments[v.Player] = struct{}{}
+					}
+				}
+				if len(assignments) != c.usersAssigned {
+					t.Error(assignments)
+				}
+			})
+		}
 	})
 
 	t.Run("swap", func(t *testing.T) {