Highly Performant & Scalable Ultima Online Server Emulator
https://www.modernuo.com
c-sharpcsharpcsharp-coredotnetdotnet-coreemulatorgplgplv3mmommo-enginemmorpgmmorpg-serveronlinerpgrunuoserverservuoultimaultima-onlineuo
## Feature Flag System A runtime feature flag system for dynamically enabling/disabling game systems and blocking specific game elements without server restarts. ### Overview Two types of controls: 1. Feature Flags - Named boolean flags that gate entire systems (trading, PvP, vendors, housing, etc.) 2. Dynamic Blocks - Block specific gumps, items, skills, or spells by type All changes are persisted to JSON, broadcast to online staff, and bypass-able by administrators. ### Predefined Flags ``` ┌─────────────────┬──────────┬─────────────────────────────────────┐ │ Flag │ Category │ Description │ ├─────────────────┼──────────┼─────────────────────────────────────┤ │ player_trading │ Economy │ Allow secure trades between players │ ├─────────────────┼──────────┼─────────────────────────────────────┤ │ vendor_purchase │ Economy │ Allow purchasing from NPC vendors │ ├─────────────────┼──────────┼─────────────────────────────────────┤ │ vendor_sell │ Economy │ Allow selling to NPC vendors │ ├─────────────────┼──────────┼─────────────────────────────────────┤ │ player_vendors │ Economy │ Allow player vendor interactions │ ├─────────────────┼──────────┼─────────────────────────────────────┤ │ bank_access │ Economy │ Allow bank box access │ ├─────────────────┼──────────┼─────────────────────────────────────┤ │ house_placement │ Housing │ Allow new house placements │ ├─────────────────┼──────────┼─────────────────────────────────────┤ │ boat_placement │ Housing │ Allow new boat placements │ ├─────────────────┼──────────┼─────────────────────────────────────┤ │ bulk_orders │ Crafting │ Allow bulk order deeds │ ├─────────────────┼──────────┼─────────────────────────────────────┤ │ pvp_combat │ Combat │ Allow player vs player combat │ └─────────────────┴──────────┴─────────────────────────────────────┘ ``` ### Commands #### Feature Flags ``` ┌────────────────────────────────────────────────────┬───────────────────────┐ │ Command │ Description │ ├────────────────────────────────────────────────────┼───────────────────────┤ │ [FeatureFlag <key> on|off|toggle|info │ Manage a feature flag │ ├────────────────────────────────────────────────────┼───────────────────────┤ │ [FF <key> on|off │ Shorthand alias │ ├────────────────────────────────────────────────────┼───────────────────────┤ │ [FeatureFlag <key> create <category> <desc> │ Create a custom flag │ ├────────────────────────────────────────────────────┼───────────────────────┤ │ [FeatureFlag <key> delete │ Delete a custom flag │ ├────────────────────────────────────────────────────┼───────────────────────┤ │ [FeatureList [flags|gumps|items|skills|spells|all] │ List all flags/blocks │ ├────────────────────────────────────────────────────┼───────────────────────┤ │ [FeatureAdmin │ Open the admin gump │ └────────────────────────────────────────────────────┴───────────────────────┘ ``` #### Gump Blocks ``` ┌────────────────────────────────┬──────────────────────────────────────────────────────┐ │ Command │ Description │ ├────────────────────────────────┼──────────────────────────────────────────────────────┤ │ [BlockGump <typeName> [reason] │ Block a gump type from displaying │ ├────────────────────────────────┼──────────────────────────────────────────────────────┤ │ [UnblockGump <typeName> │ Remove a gump block │ ├────────────────────────────────┼──────────────────────────────────────────────────────┤ │ [ListGumps [self] │ List open gumps on a player (for finding type names) │ └────────────────────────────────┴──────────────────────────────────────────────────────┘ ``` #### Item Blocks ``` ┌────────────────────────────────────────────────┬───────────────────────────────┐ │ Command │ Description │ ├────────────────────────────────────────────────┼───────────────────────────────┤ │ [BlockItemUse <typeName|target> [reason] │ Block item use │ ├────────────────────────────────────────────────┼───────────────────────────────┤ │ [BlockItemEquip <typeName|target> [reason] │ Block item equipping │ ├────────────────────────────────────────────────┼───────────────────────────────┤ │ [BlockItemContainer <typeName|target> [reason] │ Block container access │ ├────────────────────────────────────────────────┼───────────────────────────────┤ │ [UnblockItemUse <typeName> │ Remove use block │ ├────────────────────────────────────────────────┼───────────────────────────────┤ │ [UnblockItemEquip <typeName> │ Remove equip block │ ├────────────────────────────────────────────────┼───────────────────────────────┤ │ [UnblockItemContainer <typeName> │ Remove container access block │ └────────────────────────────────────────────────┴───────────────────────────────┘ ``` Item block commands create an entry if one doesn't exist, or flip the relevant flag on an existing entry. Unblock commands only clear their specific flag -- the entry is removed when all flags (use/equip/container) are off. #### Skill & Spell Blocks ``` ┌──────────────────────────────────────┬──────────────────────┐ │ Command │ Description │ ├──────────────────────────────────────┼──────────────────────┤ │ [BlockSkill <SkillName> [reason] │ Block a skill │ ├──────────────────────────────────────┼──────────────────────┤ │ [UnblockSkill <SkillName> │ Remove a skill block │ ├──────────────────────────────────────┼──────────────────────┤ │ [BlockSpell <SpellTypeName> [reason] │ Block a spell │ ├──────────────────────────────────────┼──────────────────────┤ │ [UnblockSpell <SpellTypeName> │ Remove a spell block │ └──────────────────────────────────────┴──────────────────────┘ ``` ### Architecture - Static bool classes for hot-path checks (no dictionary lookups): ServerFeatureFlags (Server project) and ContentFeatureFlags (UOContent) - Synced automatically by FeatureFlagManager.SyncStaticFlag() when flags change - Predefined flags loaded from Distribution/Configuration/FeatureFlags/default-flags.json - Runtime state persisted to Configuration/FeatureFlags/*.json (flags, gump-blocks, item-blocks, skill-blocks, spell-blocks) - Admin gump with tabbed UI for managing all block types, per-entry PropertiesGump editing, and pagination - All staff at AccessLevel.GameMaster+ bypass dynamic blocks; AccessLevel.Administrator+ bypass feature flags ### Hook Points Hook: Player trading Location: Mobile.OpenTrade Mechanism: ServerFeatureFlags.PlayerTrading ──────────────────────────────────────── Hook: PvP combat Location: Mobile.CanBeHarmful Mechanism: ServerFeatureFlags.PvPCombat ──────────────────────────────────────── Hook: Bank access Location: BankBox.Open() Mechanism: ServerFeatureFlags.BankAccess ──────────────────────────────────────── Hook: Vendor buy/sell Location: BaseVendor Mechanism: ContentFeatureFlags.VendorPurchase/Sell ──────────────────────────────────────── Hook: Player vendors Location: PlayerVendor Mechanism: ContentFeatureFlags.PlayerVendors ──────────────────────────────────────── Hook: House placement Location: HousePlacement.Check() Mechanism: ContentFeatureFlags.HousePlacement (returns BadRegionTemp) ──────────────────────────────────────── Hook: Boat placement Location: BaseBoatDeed.OnDoubleClick/OnPlacement Mechanism: ContentFeatureFlags.BoatPlacement ──────────────────────────────────────── Hook: Bulk orders Location: SmallBOD/LargeBOD Mechanism: ContentFeatureFlags.BulkOrders ──────────────────────────────────────── Hook: Gump display Location: GumpSystem.SendGump Mechanism: FeatureFlagManager.IsGumpBlocked ──────────────────────────────────────── Hook: Item use Location: PlayerMobile.AllowItemUse Mechanism: FeatureFlagManager.IsItemUseBlocked ──────────────────────────────────────── Hook: Item equip Location: PlayerMobile.CheckEquip Mechanism: FeatureFlagManager.IsItemEquipBlocked ──────────────────────────────────────── Hook: Container access Location: BaseContainer.DisplayTo Mechanism: FeatureFlagManager.IsContainerAccessBlocked ──────────────────────────────────────── Hook: Skill use Location: PlayerMobile.AllowSkillUse Mechanism: FeatureFlagManager.IsSkillBlocked ──────────────────────────────────────── Hook: Spell casting Location: Spell.Cast / Spellbook.CastSpellRequest Mechanism: FeatureFlagManager.IsSpellBlocked |
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| .config | ||
| .github | ||
| Distribution/Data | ||
| docs | ||
| Projects | ||
| .editorconfig | ||
| .gitattributes | ||
| .gitignore | ||
| azure-pipelines.yml | ||
| CODE_OF_CONDUCT.md | ||
| CONTRIBUTING.md | ||
| Directory.Build.props | ||
| FAQ.md | ||
| global.json | ||
| LICENSE | ||
| mkdocs.yml | ||
| ModernUO.sln | ||
| publish.cmd | ||
| 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
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
- Run
./publish.cmd [release|debug (default: release)] [os] [arch (default: x64)]os- Supported operating systemsarchx64- Intel/AMD 64-bitarm64- ARM 64-bit (Windows not supported)
Linux Prerequisites
Fedora, CentOS, RHEL, etc
dnf upgrade --refresh -y
# CentOS does not come with EPEL enabled
dnf install -y epel-release epel-next-release
dnf install -y findutils libicu libdeflate-devel zstd libargon2-devel liburing-devel
Ubuntu, Debian, etc
apt-get update -y
apt-get install -y libicu-dev libdeflate-dev zstd libargon2-dev liburing-dev
OSX Requirements
brew install icu4c libdeflate zstd argon2
Running the Server
- Follow the publish instructions
- Run
ModernUO.exeordotnet ModernUO.dllfrom theDistributiondirectory
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