diff --git a/SVSim.Database/Repositories/Guild/GuildRepository.cs b/SVSim.Database/Repositories/Guild/GuildRepository.cs
index 28a9974e..d874e332 100644
--- a/SVSim.Database/Repositories/Guild/GuildRepository.cs
+++ b/SVSim.Database/Repositories/Guild/GuildRepository.cs
@@ -70,10 +70,11 @@ public sealed class GuildRepository : IGuildRepository
         return await q.Take(resultCap).ToListAsync(ct);
     }
 
-    public async Task UpdateActivityAndJoinConditionAsync(int guildId, int? activity, int? joinCondition, CancellationToken ct = default)
+    public async Task UpdateActivityAndJoinConditionAsync(int guildId, int? activity, int? joinCondition, string? name = null, CancellationToken ct = default)
     {
         var guild = await _db.Guilds.FirstOrDefaultAsync(g => g.GuildId == guildId, ct);
         if (guild is null) return;
+        if (!string.IsNullOrWhiteSpace(name)) guild.Name = name;
         if (activity.HasValue) guild.Activity = (Entities.Guild.GuildActivity)activity.Value;
         if (joinCondition.HasValue) guild.JoinCondition = (Entities.Guild.GuildJoinCondition)joinCondition.Value;
         await _db.SaveChangesAsync(ct);
diff --git a/SVSim.Database/Repositories/Guild/IGuildRepository.cs b/SVSim.Database/Repositories/Guild/IGuildRepository.cs
index e5b41b91..ac5a7446 100644
--- a/SVSim.Database/Repositories/Guild/IGuildRepository.cs
+++ b/SVSim.Database/Repositories/Guild/IGuildRepository.cs
@@ -25,8 +25,8 @@ public interface IGuildRepository
         string name, int activity, int joinCondition, int memberBucket,
         int maxMemberCap, int resultCap, CancellationToken ct = default);
 
-    /// <summary>Updates activity and/or join_condition. Only non-null fields are written.</summary>
-    Task UpdateActivityAndJoinConditionAsync(int guildId, int? activity, int? joinCondition, CancellationToken ct = default);
+    /// <summary>Updates name, activity, and/or join_condition. Only non-null fields are written.</summary>
+    Task UpdateActivityAndJoinConditionAsync(int guildId, int? activity, int? joinCondition, string? name = null, CancellationToken ct = default);
 
     /// <summary>Overwrites the description field.</summary>
     Task UpdateDescriptionAsync(int guildId, string description, CancellationToken ct = default);
diff --git a/SVSim.Database/Services/Guild/GuildService.cs b/SVSim.Database/Services/Guild/GuildService.cs
index af0d0ec2..547faf34 100644
--- a/SVSim.Database/Services/Guild/GuildService.cs
+++ b/SVSim.Database/Services/Guild/GuildService.cs
@@ -129,12 +129,14 @@ public sealed class GuildService : IGuildService
         if (m is null) return new(GuildOpResultCode.NotInGuild);
         if (m.Role != GuildRole.Leader) return new(GuildOpResultCode.PermissionDenied);
 
+        if (req.Name is not null && (string.IsNullOrWhiteSpace(req.Name) || req.Name.Length > 64))
+            return new(GuildOpResultCode.NameInvalid);
         if (req.Activity.HasValue && req.Activity.Value is < 1 or > 16)
             return new(GuildOpResultCode.NameInvalid);
         if (req.JoinCondition.HasValue && req.JoinCondition.Value is < 1 or > 3)
             return new(GuildOpResultCode.NameInvalid);
 
-        await _guilds.UpdateActivityAndJoinConditionAsync(m.GuildId, req.Activity, req.JoinCondition, ct);
+        await _guilds.UpdateActivityAndJoinConditionAsync(m.GuildId, req.Activity, req.JoinCondition, req.Name, ct);
         return GuildOpResult.Ok;
     }
 
diff --git a/SVSim.Database/Services/Guild/GuildServiceTypes.cs b/SVSim.Database/Services/Guild/GuildServiceTypes.cs
index 04ac0083..df0ab382 100644
--- a/SVSim.Database/Services/Guild/GuildServiceTypes.cs
+++ b/SVSim.Database/Services/Guild/GuildServiceTypes.cs
@@ -37,4 +37,4 @@ public sealed record GuildFullView(
 public sealed record GuildSearchEntry(Entities.Guild.Guild Guild, int MemberNum);
 
 public sealed record CreateGuildRequest(string Name, int Activity, int JoinCondition);
-public sealed record UpdateGuildRequest(int? Activity, int? JoinCondition);
+public sealed record UpdateGuildRequest(int? Activity, int? JoinCondition, string? Name = null);
diff --git a/SVSim.EmulatedEntrypoint/Controllers/GuildController.cs b/SVSim.EmulatedEntrypoint/Controllers/GuildController.cs
index 9cc1aebf..9183b705 100644
--- a/SVSim.EmulatedEntrypoint/Controllers/GuildController.cs
+++ b/SVSim.EmulatedEntrypoint/Controllers/GuildController.cs
@@ -88,7 +88,8 @@ public sealed class GuildController : SVSimController
         if (!TryGetViewerId(out var viewerId)) return Unauthorized();
         int? activity = req.Activity != 0 ? req.Activity : null;
         int? joinCondition = req.JoinCondition != 0 ? req.JoinCondition : null;
-        var r = await _guild.UpdateAsync(viewerId, new(activity, joinCondition), ct);
+        string? name = string.IsNullOrWhiteSpace(req.GuildName) ? null : req.GuildName;
+        var r = await _guild.UpdateAsync(viewerId, new(activity, joinCondition, name), ct);
         if (!r.IsOk) return WireError();
 
         var m = await _db.GuildMembers.FirstOrDefaultAsync(m => m.ViewerId == viewerId, ct);
@@ -97,10 +98,8 @@ public sealed class GuildController : SVSimController
         if (guild is null) return WireError();
         var memberCount = await _db.GuildMembers.CountAsync(x => x.GuildId == guild.GuildId, ct);
         var leader = await _db.Viewers.AsNoTracking().FirstOrDefaultAsync(v => v.Id == guild.LeaderViewerId, ct);
-        return new GuildUpdateResponse
-        {
-            Guild = new GuildDetailSubTree { Detail = ToDetailDto(guild, memberCount, leader?.DisplayName ?? "") }
-        };
+        // GuildUpdateTask.Parse() reads data["guild"] directly as GuildDetailInfo — flat, no "detail" wrapper.
+        return new GuildUpdateResponse { Guild = ToDetailDto(guild, memberCount, leader?.DisplayName ?? "") };
     }
 
     [HttpPost("update_description")]
@@ -112,7 +111,7 @@ public sealed class GuildController : SVSimController
     }
 
     [HttpPost("update_emblem")]
-    public async Task<ActionResult<GuildUpdateResponse>> UpdateEmblem([FromBody] GuildUpdateEmblemRequest req, CancellationToken ct)
+    public async Task<ActionResult<GuildUpdateEmblemResponse>> UpdateEmblem([FromBody] GuildUpdateEmblemRequest req, CancellationToken ct)
     {
         if (!TryGetViewerId(out var viewerId)) return Unauthorized();
         var r = await _guild.UpdateEmblemAsync(viewerId, req.EmblemId, ct);
@@ -124,7 +123,8 @@ public sealed class GuildController : SVSimController
         if (guild is null) return WireError();
         var memberCount = await _db.GuildMembers.CountAsync(x => x.GuildId == guild.GuildId, ct);
         var leader = await _db.Viewers.AsNoTracking().FirstOrDefaultAsync(v => v.Id == guild.LeaderViewerId, ct);
-        return new GuildUpdateResponse
+        // GuildEmblemUpdateTask.Parse() reads data["guild"]["detail"] — nested wrapper required.
+        return new GuildUpdateEmblemResponse
         {
             Guild = new GuildDetailSubTree { Detail = ToDetailDto(guild, memberCount, leader?.DisplayName ?? "") }
         };
diff --git a/SVSim.EmulatedEntrypoint/Models/Dtos/Guild/GuildUpdateResponse.cs b/SVSim.EmulatedEntrypoint/Models/Dtos/Guild/GuildUpdateResponse.cs
index 9bcf4206..51e68957 100644
--- a/SVSim.EmulatedEntrypoint/Models/Dtos/Guild/GuildUpdateResponse.cs
+++ b/SVSim.EmulatedEntrypoint/Models/Dtos/Guild/GuildUpdateResponse.cs
@@ -5,11 +5,22 @@ using SVSim.EmulatedEntrypoint.Models.Dtos.Common.Guild;
 namespace SVSim.EmulatedEntrypoint.Models.Dtos.Guild;
 
 /// <summary>
-/// Response for POST /guild/update and POST /guild/update_emblem.
-/// Returns the full updated guild detail sub-tree; client merges without re-fetching members.
+/// Response for POST /guild/update.
+/// GuildUpdateTask.Parse() reads data["guild"] directly as GuildDetailInfo — flat, no "detail" wrapper.
 /// </summary>
 [MessagePackObject]
 public class GuildUpdateResponse
+{
+    [JsonPropertyName("guild"), Key("guild")]
+    public GuildDetailDto Guild { get; set; } = new();
+}
+
+/// <summary>
+/// Response for POST /guild/update_emblem.
+/// GuildEmblemUpdateTask.Parse() reads data["guild"]["detail"] — requires the nested wrapper.
+/// </summary>
+[MessagePackObject]
+public class GuildUpdateEmblemResponse
 {
     [JsonPropertyName("guild"), Key("guild")]
     public GuildDetailSubTree Guild { get; set; } = new();
diff --git a/SVSim.UnitTests/Wire/GuildWireShape.cs b/SVSim.UnitTests/Wire/GuildWireShape.cs
index effd1d6d..cb6876b8 100644
--- a/SVSim.UnitTests/Wire/GuildWireShape.cs
+++ b/SVSim.UnitTests/Wire/GuildWireShape.cs
@@ -1,5 +1,6 @@
 using NUnit.Framework;
 using System.Text.Json;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Common.Guild;
 using SVSim.EmulatedEntrypoint.Models.Dtos.Guild;
 
 namespace SVSim.UnitTests.Wire;
@@ -35,6 +36,55 @@ public class GuildWireShape
         Assert.That(first.GetProperty("emblem_id").GetString(), Is.EqualTo("100000001"));
     }
 
+    private static GuildDetailDto SampleDetail => new()
+    {
+        GuildId = 100_000_001,
+        GuildName = "X",
+        LeaderName = "L",
+        LeaderViewerId = 7,
+        Activity = 1,
+        JoinCondition = 1,
+        MemberNum = 1,
+        GuildEmblemId = 100_000_000L,
+        Description = "",
+    };
+
+    [Test]
+    public void GuildUpdate_response_serializes_with_flat_guild_detail()
+    {
+        // GuildUpdateTask.Parse() reads data["guild"] as GuildDetailInfo directly — no "detail" wrapper.
+        var resp = new GuildUpdateResponse { Guild = SampleDetail };
+        var json = JsonSerializer.Serialize(resp, Opts);
+        using var doc = JsonDocument.Parse(json);
+        var guild = doc.RootElement.GetProperty("guild");
+
+        // guild_id must be DIRECTLY under "guild"
+        Assert.That(guild.TryGetProperty("guild_id", out var gid), Is.True, "guild_id must be directly under guild");
+        Assert.That(gid.GetString(), Is.EqualTo("100000001"));
+
+        // No nested "detail" wrapper
+        Assert.That(guild.TryGetProperty("detail", out _), Is.False, "no detail wrapper for /guild/update");
+    }
+
+    [Test]
+    public void GuildUpdateEmblem_response_serializes_with_nested_detail()
+    {
+        // GuildEmblemUpdateTask.Parse() reads data["guild"]["detail"] — wrapper is required.
+        var resp = new GuildUpdateEmblemResponse
+        {
+            Guild = new GuildDetailSubTree { Detail = SampleDetail }
+        };
+        var json = JsonSerializer.Serialize(resp, Opts);
+        using var doc = JsonDocument.Parse(json);
+        var guildNode = doc.RootElement.GetProperty("guild");
+
+        Assert.That(guildNode.TryGetProperty("detail", out var detail), Is.True, "detail wrapper must exist for /guild/update_emblem");
+        Assert.That(detail.GetProperty("guild_id").GetString(), Is.EqualTo("100000001"));
+
+        // guild_id must NOT be directly under "guild"
+        Assert.That(guildNode.TryGetProperty("guild_id", out _), Is.False, "guild_id must be inside detail, not at guild level");
+    }
+
     [Test]
     public void GuildInfo_non_joined_serializes_to_prod_shape()
     {