## Summary
After #2670, `BaseCreature` stores one master. Callers still reached it through three differently gated names plus hand-rolled combinations of the `Controlled`/`Summoned` flags. Each gate is now one named view:
| Member | Definition | Meaning |
|---|---|---|
| `Master` | the reference; its setter does the follower bookkeeping; serialized as before | whoever the creature answers to |
| `ControlMaster` | `Controlled ? Master : null` | the owner |
| `SummonMaster` | `Summoned ? Master : null` | the summoner |
| `GetMaster()` | `ControlMaster ?? SummonMaster` | who answers for the creature |
`ControlMaster` and `SummonMaster` stay settable so custom code keeps compiling: both setters assign `Master`. There is no guard, so a write through either one can read back as null until the matching flag is set.
An enraged creature is the one shape with a master and neither flag. It keeps its meer through `Master`, while `GetMaster()` stays null, so the meer never answers for it (notoriety, kill credit).
Readers move onto the view they mean:
- "Owner or summoner" pairs and `ControlMaster ?? SummonMaster` collapse into `GetMaster()`: pack instinct, familiars, golem, house access, mounts, pack horse, Solen friendship, spell target and guild checks, and the `[` pet command.
- Checks such as `Controlled && ControlMaster == from` drop the flag the view already applies. Checks that don't reduce keep it: `Controlled && ControlMaster != from`, a possibly-null `from`, and `MageAI.CanDispel`'s `Summoned &&`.
**No behavior change, save format unchanged** (the schema generator produces no diff). Edge cases for custom code and shard operators:
- `SummonMaster = x` on a plain pet now replaces its owner (#2670 made that a no-op), and `ControlMaster = null` on an uncontrolled summon now clears its caster (it did nothing before).
- `SpellHelper.GetGuildFor` no longer falls back to an enraged creature's meer. Meer mages have no guild.
## Docs
- `dev-docs/content-patterns.md` § Masters: which view answers which question, how to set a master, and which flag checks are redundant.
- `dev-docs/runuo-migration-docs/09-items-mobiles-creatures.md` § Masters: RunUO's two-field reads mapped onto the views, plus the gotcha for creatures that set `SummonMaster` without `Summoned` (the write compiles, the read now returns null; use `Master`).
- The `modernuo-content-patterns` and `migrate-items-mobiles` skills point at both.
## Test plan
- [x] `MasterViewsTests`: all four views across wild, pet, controlled summon, uncontrolled summon and enraged shapes; reassigning `Master` moves follower slots; `SetControlMaster(null)` keeps an uncontrolled summon's caster; deleting a summon returns the caster's slots
- [x] Serialization tests updated to the new views (round-trip, legacy v22, v23 migration)
- [x] UOContent.Tests (1178 passed, 2 skipped) and Server.Tests (907) green
> [!IMPORTANT]
> **Breaking change to API to fix NPC AI issues**
## Symptom
`FamiliarAITests.HiddenCaster_FamiliarRefusesRetaliation` fails on main at `Assert.False(wolf.Warmode)`: the familiar's `Combatant` stays null as intended, but it is left in war stance. In-game the familiar of a hidden caster flips into warmode for a tick when struck, until `FamiliarAI.StandDown()` clears it on the next think.
CI never saw it because the familiar tests are `SkippableFact` (they need client tiledata).
## Root cause
#2644 and #2645 landed a day apart and are individually correct but conflict at one seam.
Since #2645, a familiar (`Commandable == false`) is no longer "told to stand down", so `BaseCreature.AggressiveAction` continues past `AIObject.OnAggressiveAction(aggressor)` to its generic fallback:
```cs
else if (Combatant == null && !BardPacified)
{
Warmode = true;
Combatant = aggressor;
}
```
`FamiliarAI.OnAggressiveAction` had already declined (caster hidden), but the hook was `void`, so the creature could not tell. The fallback raised `Warmode` before `BaseFamiliar.Combatant` vetoed the target.
## Fix
This is the follow-up agreed in #2645: the retaliation policy moves into a virtual `BaseAI.OnAggressiveAction(aggressor) -> bool`.
- **`BaseAI.OnAggressiveAction`** now holds the stand-down verdict, the closer-aggressor swap (`PreferCloserAggressor`), and the `IssueOrder(Attack)` vs `Combatant =` decision. Returns `false` when the creature stands down.
- **`BaseCreature.AggressiveAction`** keeps only bookkeeping — `ControlMaster.Aggressors` entry, `StopFlee`, `ForceReacquire`, ethics `FinishShield` — keyed off the return, so an AI that declines is never second-guessed.
- **`FamiliarAI`** overrides the whole policy: no orders to stand down on, never fights for a hidden caster or a hidden aggressor.
Behaviour for every other AI is unchanged. Moving the fallback ahead of `StopFlee`/`ForceReacquire` is order-safe: both are pure field resets, `IssueAttack` does not `Think()`, and `OnCombatantChange` only derives `Warmode`.
Two commits: the first is the minimal `bool` hook that alone fixes the test, the second the policy move.
## Not changed (noted for later)
- `Warmode = true; Combatant = x;` (also in `FamiliarAI.Act`, `IssueAttack`) is redundant when the setter accepts — `BaseCreature.OnCombatantChange` derives `Warmode` — and is the dangling-warmode hazard whenever a `Combatant` setter vetoes.
- Since #2614 a stood-down pet skips the ethics `FinishShield`; RunUO ran it unconditionally. Preserved as-is.
## Tests
`HiddenCaster_FamiliarRefusesRetaliation` fails on main and passes here. Full `UOContent.Tests`: 1126 passed, 0 failed, 2 skipped (spawner fixture capture + benchmark).
## Summary
`Mobile.DamageEntries` was a `List<DamageEntry>` allocated for every mobile, including the ~99% that never take damage. It is now an inline `ValueLinkList<DamageEntry>` (24 bytes in the `Mobile` object, no separate allocation) ordered least recent → most recent.
- `DamageEntry` implements `IValueLinkListNode<DamageEntry>`.
- `RegisterDamage` moves the entry to the tail in O(1) instead of `Remove` + `Add` on a list.
- Expired entries are always a head prefix, so pruning walks from the head and stops at the first live entry. The `DamageEntries` getter prunes on access.
- `DamageEntries` is exposed as `ref readonly`; enumerate with `foreach` or `.ByDescending()`. Mutation goes through `RegisterDamage` / `ClearDamageEntries`.
- `BaseCreature.GetLootingRights` and `BaseCreature.ComputeBonusDamage` take `in ValueLinkList<DamageEntry>`; all callers compile unchanged. Files that `foreach` over `DamageEntries` need `using Server.Collections;` for the enumerator extension.
- RunUO migration docs (`dev-docs/runuo-migration-docs/09`, `11`) and the `migrate-items-mobiles` skill document the change.
Saves one object and 16 bytes per mobile (~8 MB and 500k gen2 objects on a 500k world). Second of three PRs from the lazy per-mobile collections design (first: #2604). Branched from `main`; the two diffs touch disjoint hunks of `Mobile.cs`.
## Breaking change
- `Mobile.DamageEntries` is no longer a `List<DamageEntry>`. Indexing, `.Clear()`, `.Add()`, `.Remove()` no longer compile; use `foreach`, `.ByDescending()`, `.Count`, `ClearDamageEntries()`, and `RegisterDamage`. Calling a `ValueLinkList` mutator on the `ref readonly` property compiles but operates on a copy while still unlinking the real nodes; do not.
- `BaseCreature.GetLootingRights` and `BaseCreature.ComputeBonusDamage` signatures changed to `(in ValueLinkList<DamageEntry>, …)`.
Save format is untouched: damage entries are not serialized.
## Behavior
Recency order, `allowSelf`, tie-breaking in `FindMostTotal`/`FindLeastTotal` (most recent wins), `Responsible` accounting, and loot-rights ordering are unchanged and covered by the new `DamageEntryTests` and `LootingRightsTests`.
## Testing
- `dotnet build -c Release` clean.
- New `DamageEntryTests` and `LootingRightsTests` plus full `Server.Tests` and `UOContent.Tests`.
Fixes walk-up aggro latency (up to a full 10 s of obliviousness) and hardens the reacquire gate so no state can silence acquisition, while turning `AcquireOnApproach` into the reaction-time knob for future per-creature intelligence tuning.
### Why
`AcquireFocusMob` re-armed the 10 s `ReacquireDelay` **before** scanning, success or failure. A creature that scanned an empty room was blind for 10 s to a player walking up — walk-up aggro latency was uniform in 0..10 s. Waking from sector sleep stacked the AI timer's 0–3 s construction stagger on top. And `NextReacquireTime` is not serialized: on hosts whose tick counter starts negative (GCP pass-through), the 0 default blocked **all** acquisition shard-wide after a restart until the counter crossed zero.
### What
**Event-driven reaction — `AcquireOnApproachDelay` (the intelligence gradient)**
- The paragon `AcquireOnApproach` bool becomes a `TimeSpan` on every creature: an enemy moving inside `AcquireOnApproachRange` (10 for all creatures — on-screen reactive aggro; the periodic scan keeps the wide `RangePerception` sweep) *clamps* the next scan to at most the delay. Repeated steps cannot shorten it further — one scan per delay period, not per step or think.
- `Zero` (paragons) also prods the AI timer: the ranked scan engages within a wheel turn — the old snap, minus the special-cased engage path. The target now comes from the normal FightMode ranking instead of whichever mobile happened to move, and the `Combatant == null` guard stops re-engage spam.
- The 2 s default reads as "took a beat to notice you"; larger values are dumber; `ReacquireDelay` alone is the oblivious floor. Mover checks are the approach logic's `IsEnemy` + `CanBeHarmful` (so pets count and hidden movers are excluded via `CanSee`), with `IsEnemy` first to cheaply reject same-team wild creatures wandering past. The check rides the `OnMovement` callback every step already pays for — no polling added.
**Gate correctness**
- Every scan re-arms the full `ReacquireDelay`, success or failure (classic semantics; reaction time is the approach path, not the poll).
- Self-healing by construction: a deadline further out than `ReacquireDelay` is an illegal state and reads as open — no wedged or wrapped value can silence acquisition beyond one delay period.
- `NextReacquireTime` is seeded from a live tick on deserialize (the GCP negative-tick blackout).
**AI timer wake**
- Activation (sector wake, spawn, resurrection) starts within a 0–256 ms spread instead of the 0–3 s construction stagger, which read as lag.
- The stagger's real job — keeping same-speed cohorts out of lock-step (the RunUO town artifact) — is now a zero-mean ±period/8 jitter on each **idle** think, so phases random-walk apart within seconds and can never re-lock. Instrumentation showed why a one-shot spread can't do this job: the timer wheel fires within ±1 ms, so with 10 creatures on a 500 ms period some pair collides on nearly the same phase ~75% of the time (birthday paradox) and then steps in the same loop iteration *forever*. Jitter is scoped to passive speed: engaged cadence stays exact, since pursuit timing anchors to real step times.
**Debug**
- The `AcquireFocusMob` scan message no longer re-arms the shared 5 s debug cooldown, which swallowed every AI's "I have detected X" transition line.
**API change** for custom scripts: `AcquireOnApproach` (bool) → `AcquireOnApproachDelay` (TimeSpan). Documented in `content-patterns.md` § Target Acquisition, `runuo-migration-docs/09` + `11`, and the migration skill checklist.
### Tests
`AcquisitionTests`: both scan outcomes honor `ReacquireDelay`; a 60 s-wedged gate still acquires; enemy movement clamps the deadline (same-team wild movers and out-of-range movers ignored); repeated movement cannot shorten below the delay; `Zero` opens the gate and prods without a direct engage. Full suite: 755 UOContent green.
Stacked on #2594. Fixes jerky creature movement (lich / Fast-bucket melee chases) by choosing the client animation flag from the actual step pace instead of a caller-supplied `run` argument, and fixes three step-pacing defects in the move budget found while verifying it with paired server/client traces.
### Why
The `Direction.Running` bit does nothing for creatures server-side (`Mobile.OnMove` reads it only for the player throttle and stealth reveal). Its whole effect is on the client, which animates each step over a fixed time selected by that bit: walk 400 ms / run 200 ms on foot, 200 / 100 ms mounted. ClassicUO queues up to 5 steps and *drops* the sixth, so a creature stepping every 300 ms while flagged as walking backs the queue up until it snaps forward — the observed jerk.
The `run` argument never carried the one fact that matters (the step interval). RunUO passed `true` in combat / `false` for pets and gated it on `dist > 5`; #2271 flipped every combat site to `false`; pets passed `currentDistance > 2`. None of that is a coherent signal.
### What
**Pace-derived run flag**
- `BaseAI.ShouldRun()`: run iff the effective step delay (move clock + badly-hurt inflation) is shorter than `Movement.WalkFootDelay` / `WalkMountDelay` (mounted or flying) — with a continuity rule: an *isolated* step (taken after standing at least a walk interval) goes out as a walk, because the client renders each step alone and a lone run-flagged step is a 200 ms dart. Only a continuing cadence flags run; a true sprinter (pace under the run interpolation) always runs, since a walk-rendered first step would flood the client's 5-step queue. This reproduces RunUO's close-in feel (its `dist > 5` gate) from first principles.
- `DoMoveImpl` stamps the bit; it is the single place the flag is set.
- `run` removed from `MoveTo`, `WalkMobileRange`, `ApproachTarget`, `MoveToPoint`, `MoveToWithGroup`, `MoveToWithCollisionAvoidance`, the move intent, and `PathFollower.Follow`. All 35 call sites updated. **API change** for custom scripts — documented in the RunUO migration docs (`09-items-mobiles-creatures.md`, `11-api-reference.md`) and `content-patterns.md` § Creature Speeds.
**Move-budget pacing fixes** (each confirmed by UTC-aligned server/client step traces)
- A stall no longer banks catch-up steps: the budget's snap-to-now released up to three steps in ~300 ms when a creature resumed chasing after standing beside its target — rendered as a teleport.
- Debt accrual removed entirely: a step landing sub-period late (think-grid vs budget misalignment during reactive mirroring) kept the remainder and fired a follow-up ~100 ms later — a dart pair. `ConsumeMoveBudget` now paces every step from when it was actually taken; in continuous pursuit the move-wake lands within wheel resolution of the deadline, so the cost is single-digit-ms drift.
- Net effect: a creature can never step faster than its pace, verified across a full chase session (zero sub-pace steps; metronomic 350 ms cadence for a 0.3 s lich).
- Test fixture now runs `Movement.Configure()` (the walk delays were 0 in tests).
### Accepted trade-off
Animal (LOW group) bodies without a run animation slide on their stand frames when flagged as running. Most are slow enough to stay flagged as walking; the client-side fallback is in ClassicUO/ClassicUO#1930.
### Tests
`RunFlagTests`: foot thresholds (0.3 / 0.125 run; 0.4 / 0.45 / 1.05 walk), flying uses the mount threshold, badly-hurt inflation flips a 0.35 s creature back to walk, a real `DoMove` stamps the bit, isolated steps drop to walk (sprinters keep running), a stall restarts the cadence with no banked steps, and a late step earns no quicker follow-up. Full suite: 837 Server + 747 UOContent green.
## Summary
Brings every serialization-related doc, skill, and the CLAUDE.md rule in line with generator **v4** (adopted in #2586/#2587). No code changes.
**Updated surface, everywhere it was referenced:**
- `[SerializableFieldSaveFlag(order)]` / `[SerializableFieldDefault(order)]` → `[SaveFlag(nameof(Should), nameof(Default))]` on the field (second method optional).
- `[TimerDrift]` + `[DeserializeTimerField(order)]` → `[DeserializeTimer(nameof(Method), wallClock)]` on the field, with the anchored-time semantics spelled out: drifting by default (downtime preserves the remaining delay, idle saves byte-stable), `wallClock: true` for absolute deadlines, restart method invoked **only when a timer was running** (no sentinel), and the timer `MigrateFrom` pattern (`XxxNext`/`XxxDelay`) for wire-format changes.
- New `[SerializableField]` documentation: the real signature (the documented `saveIf` parameter never existed) plus the setter hooks — `allowFieldChange` (`bool Method(ref T value)`: coerce/veto before assignment) and `fieldChanged` (`void Method(T oldValue, T newValue)` after) — with the generated pipeline and the SG3015/SG3018 guardrails.
- `[SerializableProperty]` guidance narrowed to its remaining purpose: custom getters and setter semantics the hooks cannot express.
- `[AnchoredDateTime]` documented alongside `[DeltaDateTime]` (now marked legacy, with the version-bump warning for converting between them).
**Files:** `dev-docs/serialization.md`, `dev-docs/timers.md`, `dev-docs/claude-skills/modernuo-serialization.md`, `dev-docs/claude-skills/modernuo-timers.md`, `dev-docs/runuo-migration-docs/02-serialization.md`, `dev-docs/runuo-migration-docs/03-timers.md`, and a condensed v4 addition to CLAUDE.md rule 9.
**Example refresh:** the skill's `BagOfSending` "custom properties" example was itself converted in #2587 — it is now quoted in its real post-conversion form as the canonical hooks example; the real-examples list points at `BaseWeapon.cs` for custom getters and `BaseLight.cs` for the drifting-timer + `MigrateFrom` pattern.
Verified by grep: zero references to the removed v3 attribute names remain anywhere in `dev-docs/` or `CLAUDE.md`.
## Summary
Hardens the **Advanced Search** engine (`Projects/UOContent/Engines/Advanced Search/`) — the GM entity finder that fans searches across background worker threads. A code review surfaced 14 defects (A–N), including a shard-crasher reachable from a single admin typo and a path that silently disables autosave for the rest of the shard's uptime. Each behavioral fix ships with a test.
Full `UOContent.Tests` suite: **530/530 green** (21 new AdvancedSearch tests).
## Fixes
### Crash / data-loss
- **A — Shard crash on a malformed Property Test.** `AdvancedSearchThreadWorker.Execute` had no `try/catch` and the worker `Thread` is foreground, so a parse throw (`Hits>abc`, `Layer=onehanded` — `Enum.Parse` was case-sensitive, `Hits>1@` — empty sub-expression indexing) terminated the process. Now: `ParseValue`/`CompareValues` use `TryParse`/`Enum.TryParse(ignoreCase)` and return no-match instead of throwing; the per-entity filter is wrapped in `try/catch` (logs + skips); empty expressions are guarded.
- **C — Overlapping searches corrupt state + brick autosave.** `_threadWorkers`/`_threadId` were `static` but `DoSearch` is an instance method; a second search (double-click / two admins) stomped shared worker state and could leave a drain waiting forever on the shared `AutoResetEvent`, so `AutoSave.SavesEnabled` was never restored. Now: an `Interlocked` re-entrancy guard rejects concurrent searches.
- **G — Autosave restore not guaranteed.** The restore lived only in the success callback. Now it's in a `finally` (plus an outer `catch` covering the synchronous setup and a `catch` on the drain body), so autosave + the guard are always released.
### Wrong results
- **D — `@`/`|` operator precedence.** `a@b|c` evaluated as `a && (b || c)` instead of `(a && b) || c`. OR now binds looser than AND (`AdvancedSearchUtilities.EvaluateBoolean`, unit-tested).
- **E — Descending sort, partial last page rendered blank** (the index decreased in descending mode and the `break` early-out killed the loop). Now a bounded `VisibleCount`-driven loop renders the last page in both directions.
- **F — Deleted entities** were not skipped (ghost rows). Now `DoEntitySearch` skips `entity.Deleted`.
- **N — Reference-type comparisons** threw (`Comparer<T>.Default.Compare` on non-`IComparable`) and compared references to a string. Now equality is by value and ordering is guarded to `IComparable` (no throw).
### Worker perf / hardening
- **H** busy-spin → `Thread.Yield()` in the drain; **I** `GetProperties()` cached per `Type`; **J** `HandleValidInternal` moved behind the cheap map/range/region filters; **K** worker threads are `IsBackground` + `Exit()` tolerates an already-terminated worker; **L** `_filter == null` guard; **M** consistent `Volatile` access on `_pause`/`_exit`.
### Documented
- **B** — the residual worker/event-loop read race is documented on `AdvancedSearchThreadWorker`: workers read live entity state concurrently with the loop, so value-type reads may be stale-but-safe and getter exceptions are swallowed; fully eliminating it would require snapshotting entity fields on the main thread (deferred).
## Notes
- New test-only seams (`TryBeginSearch`/`EndSearch`/`IsSearchInProgress`/`VisibleCount`/`TryParseValue`/`EvaluateBoolean`) are `internal` via the existing `InternalsVisibleTo("UOContent.Tests")`.
- Dead `public ParseValue<T>` removed.
- `ConcurrentDictionary` for the reflection cache is intentional — these workers are genuinely parallel.
Kamron Batman