## Summary
- **Add a self-referencing `InterpolationHandler` to `ValueStringBuilder`** that writes directly into the builder's buffer — zero intermediate allocation, works with `stackalloc`-backed builders
- **Replace all `System.Text.StringBuilder` usage** across the codebase with `ValueStringBuilder`
- **Convert `ValueStringBuilder.Create()` to `stackalloc`** at 10 sites where output length is provably bounded
- **Convert manual `Dispose()` to `using var`** where possible, and hoist loop-scoped builders outside loops with `Reset()`
- **Convert verbose `Append()` chains to `Append($"...")`** interpolation for readability
- **Add comprehensive documentation** for string handling patterns
## InterpolationHandler Design
`ValueStringBuilder` is a `ref struct`, which creates challenges for C#'s interpolated string handler pattern:
- **`ref` fields to ref structs are not allowed** (CS9050)
- **`[InterpolatedStringHandlerArgument("")]` passes struct receivers by value**, not by ref
- **`ISelfInterpolatedStringHandler` requires boxing** ref structs into interface fields
**Solution: Copy-and-reconcile pattern.** The handler receives a value copy of the builder. The copy shares the same underlying `char` buffer (`Span` points to the same `stackalloc`/pooled memory), so writes go to the original buffer. `Append()` reconciles by `this = handler._builder`, updating `_length` and any buffer references changed by `Grow()`.
This is safe because:
- The game loop is single-threaded — no concurrent access between handler construction and reconciliation
- If `Grow()` occurs in the copy, the original's stale buffer isn't accessed until `Append()` replaces it
- `Dispose()` correctly returns the reconciled buffer to the pool
## Changes by Category
### ValueStringBuilder (`Projects/Server/Buffers/ValueStringBuilder.cs`)
- Added nested `InterpolationHandler` ref struct with copy-and-reconcile pattern
- Added `Append([InterpolatedStringHandlerArgument("")] scoped ref InterpolationHandler)` method
- Removed `RawInterpolatedStringHandler` overloads (new handler replaces them)
- All `AppendFormatted` overloads delegate to existing `Append` methods (no code duplication)
- Alignment support via direct private field access (nested type privilege)
### StringBuilder → ValueStringBuilder (15 files)
Replaced all `new StringBuilder()` with `ValueStringBuilder.Create()` or `stackalloc`:
- ConPVP games: KingOfTheHill, DoubleDom, CTF, BombingRun, TourneyMatch
- ConPVP infrastructure: Tournament, Participant, TourneyParticipant
- ConPVP gumps: ArenaGump, TournamentBracketGump, AcceptTeamGump, ConfirmSignupGump
- Commands: Handlers, Logging, Add
- Other: TownCrier, SpeechLogGump, TestCenter
Key patterns:
- `sb = new StringBuilder()` reassignment → `sb.Reset()`
- `sb.AppendFormat("{0:N0}", value)` → `sb.Append($"{value:N0}")`
- `sb.Append(x).Append(y)` chains → separate statements (VSB returns void)
### Create() → stackalloc (10 files)
Converted heap-allocated builders to stackalloc where output is bounded:
- ClientVersion (32), MapSelection (160), HouseRaffleStone (48)
- HolySense (96), UnholySense (96), ClientVerification (192)
- AcceptTeamGump (64), ConfirmSignupGump (64)
- BaseWeapon (160), BaseArmor (128)
### Loop optimizations (2 files)
Hoisted `ValueStringBuilder` creation outside loops with `Reset()` per iteration:
- TourneyMatch.cs: `using var` inside for loop → stackalloc before loop
- ArenaGump.cs: `Create()` + `Dispose()` per iteration → stackalloc before loop
### Append chain → interpolation (5 files)
Converted multi-line `Append()` chains to `Append($"...")`:
- BountyMessage.cs: title switch (6 cases), paragraph (15→1 Append), description lines, closing
- AcceptTeamGump, ConfirmSignupGump, TournamentBracketGump: tournament type strings
- AdminGump: comment/tag formatting in loops
### Documentation
- `dev-docs/string-handling.md`: Full reference — construction, interpolation, disposal, decision guide
- `dev-docs/claude-skills/modernuo-string-handling.md`: Claude skill with quick reference
- `CLAUDE.md`: Added rule 17 (no StringBuilder), dev-docs table entry, skills table entry
- `dev-docs/code-standards.md`: Updated memory management section
## Test Plan
- [x] `dotnet build` — 0 errors, 0 warnings
- [x] `dotnet test` — 940/940 tests pass
- [x] 28 ValueStringBuilder tests covering all reconciliation scenarios:
- Stackalloc no-grow, stackalloc with grow (→pool transition)
- Heap no-grow, heap with grow, heap double grow
- Pre-existing content with and without grow
- Sequential multiple `Append($"...")` calls
- Mixed plain + interpolated Append
- Empty interpolation, literal-only, format specifiers
- Null string holes, ISpanFormattable types
- Dispose after stackalloc→pool grow
# Bounty Boards
<img width="717" height="382" alt="image" src="https://github.com/user-attachments/assets/455e5206-47d8-4449-805c-19b143d059e5" />
<img width="918" height="637" alt="image" src="https://github.com/user-attachments/assets/e78e1ca2-62b8-4abf-8f69-21438bb1b759" />
<img width="340" height="296" alt="image" src="https://github.com/user-attachments/assets/fd17d7e6-8c53-47df-ac58-a89ea3ef665e" />
## Setup
* Setup as part of decorate when bounty system is enabled
* Several bounty board locations with a WarriorGuard spawner in front of the board. Guard spawns and idles around 5 range.
## Tests
### ReportBountyMurdererGump
* Follows same behaviour as ReportMurdererGump
* Extracted common logic
* Didn't use staticgump due to several dynamic parts including input
* Optional bounty with validation >0 and <bankbox.total
* Murder report is honored either way
### Bounty boards
* Open bounty board with many bounties, no bounties
* Keep a bounty board open, invalidate a bounty by turning in the head, then try to click on the post of the now invalid post. As expected: does nothing
* Bounty messages use the last murder time as their post date and expire in 14 days
* Bounty boards/messages are not reliant on serialization; they use serialized fields from MurderContext to build messages when clicked.
* Bounty messages use synthetic serials so they do not have to persist bounty messages as items. They are constructed and sent as raw packets when needed.
* Players only appear on the bounty board if they are a murderer (though a non-murderer can technically still have a bounty if they decayed kills)
* Tested skin/hair color descriptions vs a dozen spot checks
### Head turn in behaviour
* Guard accepts head
* Bounty -> gives bounty
* No bounty -> generic response
* Expired head (24h) -> generic response
NOTE: CUO "latest" has a bug with bounty/bulletinmessages that causes overflow outside of the container. It has nothing to do with this PR. It is fixed here in CUO https://github.com/ClassicUO/ClassicUO/pull/1871
# Murderer title
Bounty system and "murderer" title eliminated in [pub16](https://uo.com/wiki/ultima-online-wiki/technical/previous-publishes/2002-2/publish-16-part-2-5-23rd-july/). So UO:LBR and before had bounties and murderer title.
# Pre-T2A caveat
There were differences in pre-T2A, but this cannot be currently implemented because we do not have any pre-T2A systems in general, so at least for now, behavior is consistent with later eras. Pre-T2A was a whole other ballgame, but the bounty system still worked similarly.
## Summary
- Adds the Endless Decanter of Water (introduced in Publish 66.2 / SA era)
- Players throw a full Pitcher of Water at a Water Elemental for a 10% chance to receive the decanter; the pitcher is always destroyed on impact
- Each Water Elemental can only yield one decanter; the state is persisted and previously saved elementals are migrated to the new serialization version
- The decanter auto-refills from a linked water trough when the owner empties it within 10 tiles of the stored trough location
- Linking stores a Point3D + Map snapshot, supporting both static tile troughs and addon troughs
- The decanter is blessed and displays Linked/Unlinked status in its tooltip
## Summary
- Adds `Mobile.Murderer` virtual property and consolidates kill-threshold checks across the codebase
- Tracks ping-pong count: how many times a player crosses the 5-kill murderer threshold (T2A/UOR/UOTD only, disabled on LBR+)
- Adds `[CommandProperty]` to view a player's ping-pong count via the admin panel
- After enough ping-pongs, player is permanently flagged as a murderer regardless of kill count
- Accounts for perma-red players with low kills in murderer status transition notifications
- Implements era-appropriate "I must consider my sins" speech responses:
- **T2A**: contextual cliloc flavor text (502122–502126)
- **UOR–AOS**: raw short/long-term murder counts + ping-pong count if applicable
- **SE+**: localized stats message (1114370)
- Refactors kill-report logic out of `Keywords.cs` into `PlayerMurderSystem.ReportKillsToSelf`
## Testing
- [x] Thoroughly tested and self reviewed
- [x] Test T2A "I must consider my sins" behaviour over all scenarios.
- [x] Test UOR "I must consider my sins" behaviour over all scenarios.
- [x] Test that LBR does not have ping pongs enabled (I must consider my sins)
- [x] Test serialization cross over from v0 -> v1 increments 1 ping pong if player is already red.
## Notes
* Manually setting kills to 5 does not trigger a ping pong, it must go through the actual murder system. This includes if the kills were manually set to 5 and then migrated (as manually setting kills to 5 never adds the player into the murder system - it only happens via ReportMurderer). This is arguably a bug in the existing system, but one that currently only ever happens via staff interaction.
* Thieves guild SuspendOnMurder specifically checks for kills > 0. This means a person with 0 shorts but 5 ping pongs (flagged as murderer) can steal. This may be accurate, as according to a forum post this is how it works on UOSA which is the T2A gold standard.
* This doesn't implement Pre-T2A behaviour which should be that "I must consider my sins" does nothing at all. The reason I didn't implement it for Pre-T2A is then it 100% have to sit behind a feature flag. I don't mind adding it as a feature flag, just let me know.
## Summary
- Adds `public virtual bool Murderer => Kills >= 5` property to `Mobile`, replacing ~30 scattered `Kills >= 5` / `Kills < 5` magic-number checks across the codebase
- `BaseCreature` overrides `Murderer` to also return `true` when `AlwaysMurderer` is set
- Updates `Corpse` serialization to v15, storing `_murderer` as a `bool` field (migrated from `int Kills >= 5` in earlier versions)
### Summary
Updates all calls to container.EnumerateItems() to properly dispose of the underlying PooledRefQueue so that we are properly recycling pooled arrays.
### Summary
- Fix AccountGold gold duplication exploit: When AccountGold.Enabled was true, double-clicking a BankCheck deposited
the full value to the account but then continued creating physical gold piles for the same amount, duplicating the
value
- Fix Deposit/DepositUpTo partial deposit exploit: Both methods created new max-size gold piles and checks without
first filling existing partial stacks, wasting container slots and causing premature "bank full" failures that could
be leveraged to manipulate gold distribution
- Fix BagOfSending bank stacking: Gold and BankCheck items sent via BagOfSending now use Banker.Deposit for efficient
stacking instead of naive TryDropItem, which could fail on a full bank even when existing piles had room
- Improve gold/check deposit efficiency: Banker.Deposit and Banker.DepositUpTo now top off existing gold piles (up to
60k) and bank checks (up to 1M) before creating new items, maximizing use of available container slots
### Summary
- Adds CanSpawnMobile(x, y, minZ, maxZ, canSwim, cantWalk, out spawnZ) overload for finding spawn surfaces within a Z range
- Adds CanSpawnItem(x, y, minZ, maxZ, out spawnZ) for item spawning with Surface+Impassable support (tables, furniture)
- Uses bitmask optimization inspired by Item.DropToWorld's m_OpenSlots pattern for O(1) surface/blocker checks
- HomeRange spawners now use surface detection to set proper Z bounds
### Key Changes
Map.cs:
- CanSpawnMobile with Z-range finds lowest valid surface for mobiles
- CanSpawnItem with Z-range finds lowest valid surface for items (including tables)
- CanFitItem for point-check item placement on Surface+Impassable tiles
- Bitmask approach eliminates nested loops and stackalloc arrays
Spawners:
- Simplified GetSpawnPosition using new Z-range methods
- HomeRange setter detects surface below spawner for proper Z bounds
- Consistent handling for mobiles and items
### Bug Fixes
- Water tiles (Impassable | Wet) no longer block swimming mobs
- Items can now spawn on tables/furniture (Surface+Impassable)
### Test Plan
- Run dotnet test - 631 tests pass
- Manual testing: multi-story spawning, water mobs, item spawning on tables
- Verify HomeRange spawner movement shifts bounds correctly
### Summary
This PR transitions the spawner system from a simple radius-based model to a flexible 3D boundary system.
### Core Changes
* **Replaced `HomeRange` with `SpawnBounds`**: Spawners now use a `Rectangle3D` to define spawn areas instead of a circular integer range.
* **Backward Compatibility**:
* The `HomeRange` property remains as a helper that generates square `SpawnBounds` centered on the spawner.
* Included a migration path (v10 to v11) that automatically converts old range data into new bounds during deserialization.
* **Dynamic Bounds Shifting**: If a spawner is moved, its `SpawnBounds` will automatically shift with it, provided the bounds are currently configured as a centered square.
* **New Spawn Logic**: Added `SpawnLocationIsHome` toggle. If enabled, spawned mobiles treat their exact spawn coordinates as their "Home" rather than the spawner's location.
### Implementation Details
* **Interface Updates**: Updated `ISpawner` to include `WalkingRange`, `SpawnBounds`, and `IsInSpawnBounds()`.
* **UI Enhancements**: The Spawner Controller Gump now displays "Custom" for complex bounds and allows copying of the new boundary properties between spawners.
* **Refactored Constructors**: Streamlined `BaseSpawner`, `ProximitySpawner`, and `RegionSpawner` constructors to support the new data types.
> [!IMPORTANT]
> **Developer Note**
> THIS IS A BREAKING CHANGE TO THE NEW API GUMP.
> Please give us feedback in [discord ](https://muo.gg/discord) if you have issues, need help, or have ideas for a better API change!
### Summary
* Adds support for size/style to dynamic/static builder.
* Drastically simplifies the dynamic/static builder api for AddHtml.
* Cleans up some legacy gump files.
### Summary
* Refactors AI so it is easier to read and maintain
* Fixes NPC speed issues
* Fixes pet sector AI issue that was causing stuttering
* Fixes direction snapping for Melee/Mage AI
* Refactors pet orders
* Refactors speech commands
* Removes scale speed by dex for HS+ (it was a stupid feature anyways)
