The pure SerializationGenerator conversion of `BaseCreature`, split out of #2592 so it can serve as the reference for converting every other large hand-written class in the Delta Saves project (#7, phase 3). Two behaviour changes from #2592 are deliberately not here and follow in their own PRs on top of this one: `SpeedClass`, and the collapse of `ControlMaster`/`SummonMaster` into one reference (a creature can lose or keep either independently: Blade Spirits and Energy Vortexes are summoned but never controlled, EnragedCreature and talisman summons keep a summon master with neither flag set).
## What this is
- `BaseCreature` becomes `[SerializationGenerator(23, false)]` with a `[SerializableField]` per serialized slot and `[SaveFlag]` elision on nearly every field, so a stock creature serializes to its version plus flags. Field orders run 0..53 with no gaps (54 fields).
- The hand-written reader stays as `private void Deserialize(IGenericReader reader, int version)` for every pre-codegen version (0..22); post-codegen bumps use `MigrateFrom` from here on. `[AfterDeserialization]` carries the post-load fixups main did after reading (stat timers, AI type, followers, reacquire seeding).
- `ControlMaster` and `SummonMaster` stay two independent fields with main's semantics, each elided when null.
- `DamageMin`/`DamageMax`/`ActiveSpeed`/`PassiveSpeed` are no longer virtual (nothing in the tree overrode them); comments swept to the constraints that matter.
- Direct writes to serialized backing fields outside the generated setters (`SetDamage`, `SetResistance`, the move-speed helpers, the loot flag, feed loyalty, the delete timer) call `this.MarkDirty()`, matching the #2609 standard, so the class is ready for delta saves once `Mobile` is audited.
- Schema `Server.Mobiles.BaseCreature.v23.json` regenerated by the tool (a second run produces no diff).
## Deferred to follow-up PRs
SpeedClass: the serialized `_speedClass` field, `DefaultSpeedClass` replacing the type constant, `ApplySpeedClass`/`OnSpeedClassChange`, "None means custom", the four-speeds-as-one-block elision, `NPCSpeeds.FindEntry(SpeedLevel)`, the constructor fallback to Medium, and their tests.
Master references: serializing one `Master` with a `Controlled`/`Summoned` fan-out and the `SetControlMaster` lockstep.
## Tests
UOContent.Tests 776 / Server.Tests 855 green. `BaseCreatureSerializationTests` covers: a default creature elides to version + flags; a populated creature round-trips with exact byte consumption; back-to-back saves are byte-identical; an uncontrolled summon keeps its SummonMaster; byte-authentic v22 legacy streams (replicas of main's `Serialize`) load through the legacy reader for a wild tamable, a controlled pet, a controlled summon with an anchored `SummonEnd`, and a summon-master-only creature (the EnragedCreature shape); a running delete timer round-trips through `[DeserializeTimer]`; `Friends`, `CurrentWayPoint` and `HomeMap` round-trip; a `BaseVendor` stub round-trips the generated BaseVendor v2 → generated BaseCreature v23 chain.
## Behaviour notes for reviewers
- `ActiveMoveSpeed`/`PassiveMoveSpeed` getters return the raw override (0 = inherit); `CurrentMoveSpeed` is the resolved pace.
- Speeds elided as table defaults re-snap to the current `npc-speeds.json` on load, so table edits reach unmodified spawns on restart.
- `GetSpeeds` no longer throws on the save/load path when the table has no entry for the type: saves elide against the creature's own values and loads keep the stream. Construction still throws (`InvalidOperationException`, was `KeyNotFoundException`). An elided load with no table entry would otherwise resume at speed 0, so `[AfterDeserialization]` logs once and paces it at Medium.
- `virtual` removed from `ActiveSpeed`, `PassiveSpeed`, `DamageMin`, `DamageMax` (no overrides in the tree; forks may have some).
- `ControlMaster`, `SummonMaster`, `ControlOrder`, `Tamable`, `IsParagon` are `[SerializableProperty]` over hand-written setters because follower bookkeeping must run before the assignment, which a `fieldChanged` hook cannot express; the wire format is identical.
## Prerequisites for cherry-picking
#2609 (BaseVendor is already generated on top of BaseCreature) and SerializationGenerator 4.1.0.
Follow-up to #2574, which added a `.Migrations.cs` partial to `BaseWeapon`. Pure relocation — no behaviour change.
## The inconsistency
`BaseArmor` and `BaseClothing` already kept their pre-codegen `Deserialize(reader, version)` in a `.Migrations.cs` partial, but left the `OldSaveFlag` enum and the `GetSaveFlag` helper behind in the main class file — even though every call site is in the partial:
| Class | `Deserialize` | `GetSaveFlag` / `OldSaveFlag` | Call sites outside the partial |
|---|---|---|---|
| `BaseArmor` | already in partial | in main file | 0 of 26 |
| `BaseClothing` | already in partial | in main file | 0 of 12 |
| `BaseWeapon` | in main file | in main file | — |
`BaseWeapon` had all three still inline, with its new `.Migrations.cs` holding only a `MigrateFrom`.
## After
All three follow the same layout: `MigrateFrom` newest to oldest, then the pre-codegen `Deserialize`, then `GetSaveFlag`, then `OldSaveFlag`. That moves ~290 lines of legacy read path out of `BaseWeapon.cs` — the file that needed it most at ~3,900 lines — and leaves the main class files describing only how the type behaves today.
## Reviewing this
The diff is large and almost entirely noise, so it is probably not worth reading line by line. Two checks are stronger:
- **Nothing was lost or altered.** Across each `.cs` / `.Migrations.cs` pair, the multiset of non-blank source lines is identical to `main` except for one added comment (below). The relocation was done mechanically and asserted against that invariant rather than by hand.
- **Nothing about serialization moved with the code.** Running `ModernUOSchemaGenerator` after the move emits no new migration files.
The complete set of intentional additions:
- `using System;` in each of the three partials, for the `[Flags]` attribute (implicit usings are not enabled here).
- `// Version 9 (pre-codegen)` above `BaseWeapon`'s moved `Deserialize`, matching the marker `BaseArmor` and `BaseClothing` already carry. Version 9 is correct because `BaseWeapon.v10.json` is its earliest migration schema, so codegen began at 10.
Everything else is blank-line placement.
## Verification
Full solution builds in Release with 0 errors and 0 warnings; 1516 tests pass (815 `Server.Tests`, 701 `UOContent.Tests`).
Follow-up to #2573. That change made `SmallBOD.EndCombine` require a player-crafted item, but it could only read provenance off `BaseArmor`, `BaseWeapon` and `BaseClothing`, because those are the only three classes that track it — hence the hand-enumerated `armor?.PlayerConstructed ?? clothing?.PlayerConstructed ?? weapon?.PlayerConstructed ?? false`.
The gap is structural rather than cosmetic. `PlayerConstructed` is set inside each base's `OnCraft`, so it can only ever reach types implementing `ICraftable`. Most craftables do not — the tinkering catalogue alone is largely plain `Item` subclasses — so any rule keyed on "was this actually crafted" has nothing to key on for those types.
## What changed
Provenance moves to `Item` and is stamped centrally in `CraftItem`, immediately after the item is constructed and before the `ICraftable` dispatch, covering both the AOS and T2A craft paths. The three `OnCraft` overrides drop their now-redundant assignment and inherit `Item`'s property, so no call site outside them changes — `Resmelt` and `SalvageBag` still read `armor.PlayerConstructed` and still compile unchanged. `SmallBOD`'s three-way null-coalescing chain collapses to `item.PlayerConstructed`.
`OnCraft` is only ever invoked from `CraftItem` (the other three call sites are `base.OnCraft` chaining), so removing those assignments has no other reachable effect.
## Storage cost: none
`Item`'s `SaveFlag` word is written as a fixed-width `int`, not an encoded one, so occupying bit `0x08000000` changes no record lengths. Items that are not player-constructed serialize byte for byte as before, and crafted ones differ by a single bit in a field already being written.
`Item` itself needs no version bump: a bare `SaveFlag` bit is self-describing, so records written before it existed lack it and read `false`.
## Version bumps
The three content classes do need one, since removing a serialized field changes their layout:
| Class | Version | Field removed |
|---|---|---|
| `BaseArmor` | 9 → 10 | 24 (was last, nothing renumbered) |
| `BaseClothing` | 7 → 8 | 7 (fields 8–10 shift down) |
| `BaseWeapon` | 10 → 11 | 26 (fields 27–30 shift down) |
Each gets a `MigrateFrom` for its previous version that assigns the old bool to the inherited property, so existing crafted armour, weapons and clothing keep their provenance across the upgrade. `Item.Deserialize` runs first and reads the absent bit as `false`, then the migration overwrites it — the generated `Deserialize` calls `base.Deserialize` before dispatching, so the ordering holds. `BaseWeapon` had no migrations file and gains one.
The renumbering is not stylistic: the generator requires contiguous field ordering and rejects a hole with `SG3005: Expected field 'Crafter' with order 7 but found 8`.
New schema JSONs (`BaseArmor.v10`, `BaseClothing.v8`, `BaseWeapon.v11`) are generated by `ModernUOSchemaGenerator` and committed alongside.
## One thing worth a second opinion
The new property is a plain auto-property on `Item`, so it does not call `this.MarkDirty()` the way the codegen setters it replaces did. `MarkDirty` is currently a no-op (`// TODO: Add dirty tracking back`) and no property in `Item.cs` calls it, so this matches the file as it stands — but it is worth noting if dirty tracking comes back.
## Verification
Full solution builds in Release with 0 errors and 0 warnings; 1516 tests pass (815 `Server.Tests`, 701 `UOContent.Tests`).