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.
Splits creature speed into two clocks so movement pace can be tuned without touching reaction time:
- **Think clock** — `ActiveSpeed`/`PassiveSpeed`/`CurrentSpeed`: seconds per AI decision. Unchanged in meaning, storage, and cadence.
- **Move clock** — `ActiveMoveSpeed`/`PassiveMoveSpeed` (+ resolved `CurrentMoveSpeed`): seconds per step. `0` = inherit the matching think value.
### How
- Move speeds come from optional `activeMove`/`passiveMove` in `npc-speeds.json`, are `[props`-tunable per instance (set `0` to re-inherit), and serialize (BaseCreature v22).
- `SetSpeed()` keeps its legacy one-clock semantics — sets the think clock **and clears move overrides** — so existing callers cannot half-configure a creature. `SetMoveSpeed()`/`ClearMoveSpeed()` configure movement explicitly; `ScaleMoveSpeed()` scales overrides for buffs.
- `CurrentMoveSpeed` is derived by classifying `CurrentSpeed`: a verbatim active/passive think value maps to the matching move value; a bespoke pace written directly (mount boosts, follow sprint) stays fused to both clocks. External `CurrentSpeed` writers need no changes.
- `AITimer` schedules the earlier of the two deadlines. Decisions run at the think cadence exactly as before; while a pursuit/investigation is live, the timer also wakes when the movement budget elapses and advances one step with no decisions. Steps no longer snap to the think grid, so any step delay paces smoothly on the 8ms wheel. A blocked creature schedules no move wakes.
- The movement budget is RunUO's `m_NextMove` accumulate-and-clamp at a full step, so long-run pacing averages `CurrentMoveSpeed` exactly.
### Behavior changes
- **`npc-speeds.json` buckets get RunUO `TransformMoveDelay`-parity move values**: creatures step at RunUO pace while thinking/reacting at current speed. The situational +0.1/+0.2 offsets are deliberately omitted.
- **Existing saves migrate on load**: a pre-v22 creature whose think speeds still match its npc-speeds entry (never hand-tuned) adopts the table's move values — worlds and pets pick up the new pacing without a respawn. Tuned creatures keep movement inheriting their think clock.
- **Paragons scale movement by `SpeedBuff` (1.2x)**: RunUO had no deliberate policy here — dividing by 1.2 knocked most speeds off `TransformMoveDelay`'s exact-equality table (raw pass-through, 2x+ faster), while 0.3/0.6 creatures landed back on it for ~1.33x. This applies the uniform 1.2x the buff always claimed. UnConvert snaps speeds back to exact table values within 1e-4 — /1.2 then ×1.2 drifts 0.45 and 0.9 by an ulp, which would read as hand-tuned (and defeat a future skip-table-conformant-values serialization pass); tuned speeds keep.
- **Herding paces the movement clock**: the old `CurrentSpeed` getter hack is gone. A herded creature walks at a fixed 0.3s/step — RunUO's forced pace, without its `TransformMoveDelay` inflation to 0.6 — so herding is never penalized by a slow creature. Thinking is untouched, and `CheckHerding` walks through `MoveToPoint`, so herded creatures path around obstacles.
- **Badly-hurt slowdown now inflates the step delay only** (RunUO parity), computed from the base each step. Previously it wrote `CurrentSpeed = CurrentSpeed + 0.05..0.15` back on every successful step — compounding unboundedly while hurt and slowing decisions too.
- Removes the vestigial `MoveSpeedMod` (never read, written, or serialized).
- With no bucket or per-instance move values, both clocks carry identical values and creatures pace as before.
### Testing
- Full suite passes (1557, including 12 new `MoveSpeedTests`: resolution classes, `SetSpeed` clearing, `0`-re-inherit, v22 round-trip with exact-consumption check, save migration adopt/skip, buff scale/snap, herding).
- In-game verified via local diagnostics build (per-step budget tracing): steady 700ms step cadence on a 0.3s think grid with one-step catch-up after idle, think grid unperturbed by move wakes.
Kamron Batman