Ultima III: Exodus - .NET 9 Avalonia Recreation

A faithful recreation of the classic 1983 RPG "Ultima III: Exodus" using .NET 9 and Avalonia UI for cross-platform compatibility.

Screenshots

Main Menu	Overworld	Town

Combat	Dungeon	Character Creation

Author

Lonnie Watson

Project Structure

UltimaIII.sln
├── src/
│   ├── UltimaIII.Core/          # Game logic, models, and engine (platform-agnostic)
│   │   ├── Enums/               # Game enumerations (Race, Class, TileType, etc.)
│   │   ├── Models/              # Core models (Character, Party, Item, Spell, Monster, Map)
│   │   └── Engine/              # Game engine, combat system, map generator
│   │
│   ├── UltimaIII.Avalonia/      # Avalonia UI project for rendering and input
│   │   ├── Controls/            # Custom controls (TileMapControl, CombatMapControl)
│   │   ├── Services/Audio/      # Procedural chiptune audio system
│   │   ├── ViewModels/          # MVVM ViewModels
│   │   └── Views/               # AXAML views
│   │
│   └── UltimaIII.Data/          # Game data (maps, monsters, items, spells)

Features

Character Creation System

Races: Human, Elf, Dwarf, Bobbit, Fuzzy (each with stat modifiers)
Classes: Each class has unique combat bonuses and special abilities:

Class	Combat Role	Attack	Defense	Damage	Special
Fighter	Pure warrior	+2, +1/4 lvls	+1	+2, +1/5 lvls	Best consistent melee
Cleric	Healer	—	+1, +1/5 lvls	—	+2 atk/dmg vs Undead
Wizard	Offensive caster	-2	—	-1	Relies on spells
Thief	Agile rogue	+3, +1/3 lvls	+2	—	Critical hits (15+Level %)
Paladin	Holy knight	+1, +1/5 lvls	+2	+1	+3 atk/dmg vs Undead/Demon
Barbarian	Brute	+1	—	+3, +1/4 lvls	Rage: +1 dmg per 25% HP missing
Lark	Thief-mage	+1, +1/5 lvls	+1	—	Critical hits (10+Level/2 %)
Illusionist	Wizard-thief	-1	+1	-1	Spell-focused
Druid	Nature priest	—	+1	—	+2 atk/dmg vs Demon
Alchemist	Scholar	-1	—	—	Jack-of-all-trades caster
Ranger	Wilderness warrior	+1, +1/5 lvls	+1	+1	+1 weapon range

Stats: Strength, Dexterity, Intelligence, Wisdom (range: 3-25)
Party System: Create up to 4 characters

Core Game Systems

Tile-Based World: Procedurally generated overworld, towns, and dungeons
Movement: 4-directional movement with collision detection
Terrain Types: Grass, Forest, Mountain, Water, Swamp, Lava, etc.
Time System: Day/night cycle, moon phases
Fog of War: Exploration reveals the map
Safe Zones: Towns have no random encounters
Save/Load: Persistent game saves with full party, inventory, and quest state
Screenshots: Press Ctrl+Shift+S on any screen (main menu, gameplay, combat, shops, etc.) to capture a PNG screenshot with a custom name (defaults to current screen + date)

Combat System

Turn-Based Tactical Combat: 11x11 grid
Initiative: Based on Dexterity/Speed
Player Movement: Move characters tactically during combat
Actions: Move, Attack, Cast Spell, Pass, Flee
Target Selection: Keyboard (WASD) or mouse (click to select, double-click to confirm)
Monster AI: Simple pathfinding and attack behavior
20+ Monster Types: Orcs, Skeletons, Dragons, Demons, etc.
Loot Drops: Defeated monsters can drop weapons, armor, shields, consumables, and gems based on per-monster loot tables
Gem Combat Effects: Socketed gems provide passive bonuses during combat -- bonus damage, lifesteal, damage reflection, status resistance, and more

Magic System

Wizard Spells: 19 spells (offensive, utility, teleportation)
- Includes AOE: Vas Flam (fireball), Grav Por (ice storm), Noxum (poison cloud), Dag Mentar (confusion), Xen Ang (chain lightning)
Cleric Spells: 19 spells (healing, protection, cure, resurrection, holy offense)
- Includes AOE: Vas Sanct (holy nova), An Corp (divine judgment), Sominae (sleep)
Status Cures: Sanctu cures poison; Lib Rec removes all ailments (poison, confusion, sleep, paralysis)
Combat Casting: CuresStatus spells work in combat to heal afflicted party members
Field Casting: Press C outside of combat to cast support spells — heal injured allies, cure poison or paralysis, resurrect fallen party members, and more without needing a Healer shop
Class Restrictions: Each class has access to different spell levels

Shop System

7 Shop Types: Weapon Shop, Armor Shop, Tavern, Healer, Guild, Inn, Temple
Unique Shop Names: Each town has procedurally named shops (e.g. "The Rusty Blade", "The Silver Stag")
Buy/Sell/Equip Tabs: Purchase equipment, sell items, and equip gear
Party Inventory Selling: Press Q on the Sell tab to toggle between selling from character inventory or party inventory
Services: Healing, cure, resurrection (Healer); rest to restore HP/MP (Inn); food (Tavern)
Temple: Socket gems into equipment (see Gem Socketing System below)
Class Restrictions: Equipment restricted by character class

Party Inventory System

Shared Inventory: Party-wide item storage fed by monster loot drops
Inventory Browser: Press I to open the inventory screen from anywhere (overworld, town, dungeon)
5 Filter Tabs: All, Weapons, Armor, Shields, Items
Equip from Party: Select a character and equip items directly from party inventory
Equipment Swap: Currently equipped items return to party inventory when replaced
Stackable Items: Consumables stack with quantity display (e.g. "Healing Potion x3")
Persistent: Party inventory saves and loads with the game

Town System

Procedurally Generated Towns: 32x32 maps with walls, buildings, and a central fountain square
Cobblestone Paths: Connecting main avenue, east-west roads, and the town square
Shop Signs: Readable signs next to each shop door displaying the shop name
Decorations: Flower beds, lampposts along roads, and scattered trees
Door Clearance: Automatic validation ensures decorations never block shop entrances

Quest System

18 Quests: Spanning all 8 towns with early, mid, and late game progression
3 Quest Types:
- Kill Quests: Slay a target number of specific monsters (e.g. 5 Giant Rats, 12 Undead)
- Fetch Quests: Recover quest items dropped by specific monsters in combat (e.g. Lich Phylactery from Liches)
- Explore Quests: Visit a specific dungeon level to scout and report back
Quest NPCs: Green-robed NPCs with "!" markers placed in each town — they greet you as you approach
Tavern Quests: Some quests are offered by tavern barkeeps (accessible via the Tavern shop)
Quest Chains: Late-game quests require completing prerequisites (e.g. "Destroy the Lich" unlocks after "Vampire Hunt")
Quest Log: Press J to view active quests with progress tracking (kill counts, exploration status)
Talk to NPCs: Press T when adjacent to a quest NPC to view available quests, accept new ones, or turn in completed quests
Quest Item Drops: Fetch quest items drop from specific monsters at high rates (50-80%) when the quest is active
Rewards: Gold and experience for each completed quest
Persistent: Quest progress saves and loads with the game

Map System

Overworld: 64x64 procedurally generated world with 8 towns and 4 dungeons
Towns: 32x32 with shops, paths, signs, and decorative features

Dungeon System

Each of the 4 dungeons (Doom, Fire, Time, Snake) has 8 procedurally generated levels with increasing difficulty.

Layout

32x32 maps with 9-16 rooms per level (more rooms on deeper levels)
Room size variety: Tight closets (2-3 tiles), standard rooms (4-6 tiles), and large chambers (7-9 tiles)
MST corridors: Prim's minimum spanning tree guarantees all rooms are reachable, with extra random connections creating loops and alternate paths
Wide corridors: On levels 5+, some corridors are 2 tiles wide (25% chance)
Doors: Automatically placed at corridor chokepoints; more frequent on deeper levels (20% on L1, 55% on L8)

Stairs and Portals

Stairs up: Always in the first room (entrance from previous level or surface)
Stairs down: Always present on levels 1-7, placed in the last room
Exit portals: Shimmering portals on levels 5-8 for quick return to the surface

Room Features

Every room can contain multiple features, with more in larger rooms:

Feature	Chance	Notes
Chest	20%	Contains gold scaled by level, plus a 35% chance of item drops (consumables, gems, or equipment) -- 20% chance of being trapped
Fountain	15%	Interactable water source
Trap	5% + 2% per level	More dangerous on deeper levels
Secret Door	10%	Hidden in room walls (all 4 sides); appears as a grey wall tile until revealed by Searching (Space)
Lava Cluster	3% per level	1-3 tile clusters; only on deeper levels

Chest Loot

Searching a chest (Space) awards gold and may drop an item:

Drop	Chance	Details
Gold	Always	10-100 base x (dungeon level + 1)
Consumable	10%	Healing Potion or Rations
Gem	10%	Tier scaled by dungeon level (same rates as monster gem drops)
Equipment	15%	Random weapon, armor, or shield; better gear available on deeper levels

Encounter Rate

Random encounters occur with each step: 5 + dungeon level% chance (6% on L1, 13% on L8). Larger maps mean more exploration between fights.

Tavern Recruitment

Recruitable NPCs: Each town's tavern has a randomly generated companion available
Recruit Tab: Press 3 in the tavern to browse the available NPC's stats, race, and class
Direct Recruit: If the party has an open slot (fewer than 4 members), the NPC joins immediately
Swap System: If the party is full, choose which member to leave behind at the tavern
Parked Characters: Left-behind characters remain at the tavern and can be recruited later
Persistent: Tavern NPCs and parked characters save and load with the game

Gem Socketing System

Gems are rare drops from defeated monsters that can be permanently socketed into equipment at Temples found in every town. Each gem grants a specific combat bonus depending on its type and which equipment slot it occupies. Gems cannot be purchased — they can only be found through combat or earned as quest rewards.

Gem Types and Effects

Gem	Tier	Slot	Effect
Ruby	Chipped / Flawed / Perfect	Weapon	+1 / +2 / +4 bonus damage on every attack
Sapphire	Chipped / Flawed / Perfect	Weapon	+1 / +2 / +3 attack hit bonus
Emerald	Chipped / Flawed / Perfect	Armor, Shield	+3 / +6 / +10 max HP
Diamond	Chipped / Flawed / Perfect	Weapon	+3% / +5% / +8% critical hit chance
Diamond	Chipped / Flawed / Perfect	Armor	+1 / +2 / +3 defense
Topaz	Chipped / Flawed / Perfect	Weapon	+2 / +3 / +5 bonus damage vs Undead
Topaz	Chipped / Flawed / Perfect	Armor	+1 / +2 / +3 magic defense (reduces spell damage)
Amethyst	Chipped / Flawed / Perfect	Armor, Shield	10% / 20% / 35% status effect resistance
Onyx	Chipped / Flawed / Perfect	Weapon	5% / 10% / 15% lifesteal (heal % of damage dealt)
Opal	Chipped / Flawed / Perfect	Shield	Reflect 1 / 2 / 4 damage back to melee attackers

How to Obtain Gems

Monster Drops: Every defeated monster has a chance to drop a gem based on its dungeon level. Higher dungeon levels yield rarer tiers:

Monster Level	Chipped	Flawed	Perfect
1 (Rats, Goblins)	8%	--	--
2 (Ghouls, Trolls)	12%	4%	--
3 (Wraiths, Imps)	10%	8%	--
4 (Vampires)	5%	12%	3%
5 (Liches)	--	15%	5%
6 (Daemons)	--	12%	8%
7 (Balrons)	--	10%	12%
8 (Dragons)	--	8%	15%

Quest Rewards: Four quests grant guaranteed gem rewards:

Troll Bridge (Fawn) -- Flawed Ruby
Undead Purge (Moon) -- Flawed Topaz
Daemon Bane (Devil Guard) -- Perfect Onyx
The Time Shard (Moon) -- Perfect Diamond

Equipment Socket Counts

Not all equipment has sockets. Higher-tier gear has more:

Sockets	Weapons	Armor	Shields
0	Dagger, Sling, Mace	Cloth	Small Shield
1	Short Sword, Axe, Bow, Long Sword, Staff, Crossbow	Leather, Chain Mail	Large Shield, Tower Shield
2	Halberd, Great Sword, 2H Axe, Wand	Plate Mail	--

Socketing at Temples

Enter a town and walk into the Temple building (bottom-right area of town)
Press B at the counter to enter the Temple
Select a character (A/D to cycle)
Select the equipment to socket
Select the socket slot (empty or occupied)
Select the gem from your inventory
Confirm the socketing and pay the gold cost

Socketing Costs scale by gem tier and equipment value:

Gem Tier	Equipment value up to 100g	101-300g	Over 300g
Chipped	50g	100g	150g
Flawed	150g	300g	450g
Perfect	400g	800g	1,200g

Important: Replacing a socketed gem destroys the old gem. There is no way to remove a gem without replacing it.

Audio System

OGG Music Support: Place .ogg files in Assets/Music/ to replace any synthesized track (e.g., Overworld.ogg, Combat.ogg, Town.ogg)
Automatic Fallback: Tracks without a matching OGG file use procedural chiptune synthesis
Smart Track Matching: Dungeon-specific combat tracks (e.g., CombatDoom) fall back to Combat.ogg if no specific file exists; same for dungeon exploration tracks
Procedural Chiptune Audio: Built-in synthesized music and sound effects as default
Waveform Synthesis: Square, triangle, sawtooth waves, and white noise
Cross-Platform: Uses Silk.NET.OpenAL for Windows (x64/ARM64), macOS (Intel/Apple Silicon), and Linux support
Music Tracks:
- Main Menu - Epic/mysterious arpeggios
- Overworld - Adventurous march (day/night variations)
- Town - Peaceful medieval melody
- Dungeon - Tense, foreboding atmosphere
- Combat - Fast, urgent battle music
- Victory/Defeat - Triumphant fanfare or somber dirge
Sound Effects: Footsteps, sword swings, hits, misses, spell casting, monster deaths, UI feedback, and more

Building and Running

Prerequisites

.NET 9 SDK

Build

dotnet build

Run

dotnet run --project src/UltimaIII.Avalonia

Controls

Exploration Mode

Key	Action
W / Up Arrow	Move North
S / Down Arrow	Move South
A / Left Arrow	Move West
D / Right Arrow	Move East
Space	Search
R	Rest
B	Enter Shop (when adjacent to counter)
T	Talk to quest NPC (when adjacent)
C	Cast spell (field magic — heal, cure, resurrect)
I	Open Party Inventory
J	Open Quest Log
X	Exit current location
Ctrl+Shift+S	Take screenshot
F5	Save game
F12	Quit game

Combat Mode

Key	Action
W / Up Arrow	Move character north
S / Down Arrow	Move character south
A / Left Arrow	Move character west
D / Right Arrow	Move character east
T	Attack (select target)
C	Cast spell
U	Use item (consumables)
P	Pass turn
F	Flee from combat

Target Selection (after Attack/Cast)

Input	Action
WASD / Arrows	Move target cursor
Enter / Space	Confirm target
Escape	Cancel
Mouse Click	Select target tile
Mouse Double-Click	Select and confirm target

Inventory Browser

Key	Action
W/S / Up/Down	Browse items
A/D / Left/Right	Switch character
Enter / Space	Equip selected item
1-5	Switch tab (All/Weapons/Armor/Shields/Items)
Tab	Cycle tabs
Esc / I	Close inventory

Shop Mode

Key	Action
W/S / Up/Down	Browse items
A/D / Left/Right	Switch character
Enter / Space	Confirm purchase/sale/equip/recruit
1-4	Switch tab (Buy/Sell/Recruit/Equip/Services)
Tab	Cycle tabs
Q	Toggle sell source (Character/Party inventory)
Esc	Leave shop

Field Spell Casting (C key)

Key	Action
W/S / Up/Down	Browse casters, spells, or targets
Enter / Space	Select caster / cast spell / confirm target
Esc / C	Go back / close

Quest Log (J key)

Key	Action
W/S / Up/Down	Browse quests
Esc / J	Close quest log

Temple (B key at temple counter)

Key	Action
W/S / Up/Down	Browse equipment, sockets, or gems
A/D / Left/Right	Switch character
Enter / Space	Select / confirm
Esc	Go back / close temple

Quest Dialog (T key, when adjacent to NPC)

Key	Action
W/S / Up/Down	Browse quests
Enter / Space	View details / accept / turn in
Esc	Go back / close

Custom Tile Sprites

The game supports PNG sprite overrides for any tile type. Place a 32x32 PNG in src/UltimaIII.Avalonia/Assets/sprites/ named after the tile type (lowercased). Any tile without a matching sprite falls back to code-drawn rendering.

Sprite Checklist

Overworld / Town Terrain:

Structures:

Dungeon Features:

Special:

Combat Sprites

Combat sprites also go in Assets/sprites/. Player characters use their class name, monsters use their definition ID. Combat terrain checks for combat_<terrain>.png first, then falls back to the shared terrain sprite above.

Player Classes (by class):

Monsters (by ID):

Combat Terrain (optional overrides):

combat_grass.png
combat_forest.png
combat_mountain.png
combat_floor.png

Technical Details

Framework: .NET 9
UI: Avalonia UI 11.2
Pattern: MVVM with CommunityToolkit.Mvvm
Graphics: Custom tile rendering with retro CGA/EGA color palette
Audio: Silk.NET.OpenAL for cross-platform audio, NVorbis for OGG Vorbis decoding

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

A recreation of Ultima III: Exodus, originally created by Richard Garriott (Lord British) and published by Origin Systems in 1983.

Name		Name	Last commit message	Last commit date
Screenshots		Screenshots
src		src
.gitignore		.gitignore
LICENSE		LICENSE
README.md		README.md
UltimaIII.sln		UltimaIII.sln
build.ps1		build.ps1
build.sh		build.sh

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