ModernUO Emulator
f8d2a2bacc
## Symptom Since #2614, on any shard with `taming.petsStandDownOnCommand` (default `Core.ML`), every wild creature hits `"I'm being attacked but my master told me not to fight."` when struck. Brigands still chase (acquisition is a separate path in the think loop) but the retaliation path is dead: no `OnAggressiveAction`, no `StopFlee`, no `ForceReacquire`, `Combatant` never set, and `Warmode` forced off on every hit. ## Root cause #2614 correctly added `OrderType.None` to `BaseAI.IsStandDownOrder` — a stopped pet rests on `None` and Publish 51 says it must not fight back. But the gate in `BaseCreature.AggressiveAction` never asked whether anybody could have given the order. The old predicate (`ct != Follow && ct != Stop && ct != Stay`) had only excluded wild creatures by accident: `None` was not in its set, so nothing ever needed to spell the check out. A wild creature's `_controlOrder` is always `None`. ## Fix Both halves of `AggressiveAction` now gate on `Controlled && ControlMaster != null && Commandable` — the same predicate every order entry point already uses (`OnSpeech`, context menu, `IsValidTarget`). Only a creature somebody can command has been told to stand down. That excludes, and lets fight back: | Creature | Why it was standing down | |---|---| | Wild creature | rests on `None` | | Energy vortex, blade spirits, animated weapon, animate dead | `Summoned` with a `SummonMaster` but never `Controlled`; rests on `None` | | Familiar, talisman summon, escortee, mirror image | `Controlled` with a master but `Commandable => false`; sits on a system-issued `Follow` | The last row is a deliberate behaviour change from #2614 for ML+ shards: a familiar or escortee on `Follow` no longer stands down when attacked. The publish speaks of commanded pets; a creature that cannot take an order was never told anything, and pre-ML it always fought back. Commandable summons (Summon Creature, elementals, daemons) are `Controlled` with `ControlMaster == SummonMaster`, so they stand down exactly as pets do. ## Also: stop after stay Found while testing: `all come` then `all stop` left the pet on `Stay`, ticking *"I have been ordered to stay"*. `come` rests into `Stay` on arrival (deliberate ModernUO divergence, kept), and #2614 had `IssueStop` keep a previous `Stay`. RunUO and ServUO never consult the previous order — `DoOrderStop` is "wander around here" (or `None` pre-ML) — and Publish 51 says a stopped pet *"may wander"*. `Stay` now joins `Follow`/`Guard` in `IssueStop`: stop cancels the standing order and the pet idles anchored where it stands. `Stop_WhileStaying_RemainsStayingAtOriginalPost` is replaced by `Stop_WhileStaying_CancelsToIdleNone` plus the `come, stop` repro. ## Tests `PetRetaliationTests` gains one case per row above: `WildCreature_`, `UncontrolledSummon_`, `UncommandableCreature_Retaliates_UnderStandDown`. Each fails on main and passes here; full `UOContent.Tests` green (1058 passed). |
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| .github | ||
| branding | ||
| dev-docs | ||
| Distribution/Data | ||
| Projects | ||
| tools | ||
| .cursorrules | ||
| .editorconfig | ||
| .gitattributes | ||
| .gitignore | ||
| AGENTS.md | ||
| azure-pipelines.yml | ||
| CLAUDE.md | ||
| CODE_OF_CONDUCT.md | ||
| CONTRIBUTING.md | ||
| Directory.Build.props | ||
| FAQ.md | ||
| GEMINI.md | ||
| global.json | ||
| LICENSE | ||
| ModernUO.slnx | ||
| publish.cmd | ||
| publish.ps1 | ||
| publish.sh | ||
| README.md | ||
| rider-settings.zip | ||
| Rules.ruleset | ||
| SPONSORS.md | ||
| stylecop.json | ||
| THIRD-PARTY-NOTICES | ||
| version.json | ||
ModernUO 
Ultima Online Server Emulator for the modern era!
Requirements
Supported Operating Systems
Required Frameworks
All Operating Systems
Windows
Hardware
| Use | vCPU | RAM | Storage |
|---|---|---|---|
| Development / test | 2 dedicated | 2 GB | SSD |
| Small live shard (< 50 concurrent) | 4 dedicated | 4 GB | NVMe |
| Medium (50–200) | 4–8 | 8 GB | NVMe |
| Large (200+) | 8+, high clock | 16 GB+ | NVMe |
See dev-docs/server-requirements.md for more information.
Development
Supported IDEs
Getting Started
- Install prerequisite requirements
- Clone this repository (or download the latest):
git clone https://github.com/modernuo/ModernUO.git
- Open
ModernUO.slnto start developing
Building/Publishing
Interactive Mode (Recommended for new users)
Run ./publish.cmd (Windows) or ./publish.sh (Linux/macOS) with no arguments to launch the guided build tool. It will:
- Check prerequisites (.NET SDK, native libraries)
- Walk you through configuration and platform selection
- Build and publish the server to the
Distributiondirectory - Show deployment instructions for cross-compiled builds
Command Line
./publish.cmd [release|debug] [os] [arch]
os- Supported operating systemsarchx64- Intel/AMD 64-bitarm64- ARM 64-bit
Linux Prerequisites
Fedora, CentOS, RHEL, AlmaLinux, Rocky, etc
dnf upgrade --refresh -y
# RHEL-family distributions (CentOS Stream, AlmaLinux, Rocky, RHEL) need CRB and EPEL enabled.
# Fedora skips this block.
dnf install -y dnf-plugins-core
dnf config-manager --set-enabled crb
dnf install -y epel-release
# Prerequisites
dnf install -y findutils libicu libdeflate libargon2 tzdata
Ubuntu, Debian, etc
apt-get update -y
# The ICU runtime package carries the ABI version in its name (libicu74, libicu76, …) and has no
# stable alias, so match it by pattern rather than pinning a release-specific name.
apt-get install -y '^libicu[0-9]+$' libdeflate0 libargon2-1 tzdata
Only the runtime libraries are needed — the -dev/-devel packages are not. Run
./build-tool --check-prereqs to check the current machine and print the exact packages your
release needs.
zstd is not listed because ZstdNet bundles libzstd for every platform, and liburing is not
listed because IORingGroup issues io_uring syscalls directly.
If the shard's configured time zone is a legacy alias such as US/Eastern, Debian 12 and Ubuntu
24.04 also need tzdata-legacy. See Platform Prerequisites
for what each dependency is for and what breaks without it.
OSX Requirements
brew install icu4c libdeflate argon2
Running the Server
- Follow the publish instructions
- The
Distributiondirectory is portable — copy it to your production server for deployment - Run
ModernUO.exeordotnet ModernUO.dllfrom theDistributiondirectory - On first run, the server will prompt you to configure game data file locations
Troubleshooting / FAQ
- See FAQ
Want to sponsor?
Thank you for supporting us! You can find out how by visiting the sponsors page.
Collaborators
Thanks
- RunUO Team & Community
- Voxpire, the ServUO Team & Community
- Karasho, Jaedan and the ClassicUO Community
Development Tools & Plugins provided with ♥ by
Code Signing Policy
Free code signing provided by SignPath.io, certificate by SignPath Foundation.
This program will not transfer any information to other networked systems unless specifically requested by the user or the person installing or operating it
Teams & Roles
Approvers & Committers: Development Team