That. Was. Epic. Threat of the Trinity is a masterpiece. Fenyx4
The original experience... but better. Inhouse Beta-tester
It doesn't feel like a mod... it feels like it was always part of the game. Always this way. Radscience
Finally, a triumphant return to the world of Ultima IV--with plenty of surprises for old and new players alike! Can't wait to play it again! MrKnitster
The story was cool and it was pretty hard. Well, really hard. The new Crypts were crazy. Insane! Inhouse Beta-tester

Tell Me More About...

The Features

New Major Quests

The Threat of the Trinity presents new major quests, the completion of which is critical for the peace and safety of Britannia. Ignore the quests if you wish, or complete them and leave Britannia more safe and secure once the secrets of the Codex have been uncovered.

New Crypts, Caves and Mines

Almost twice as many dungeons, means twice as much adventure! They range from simple cave systems, to complex and fiendish crypts, packed with traps and puzzles to thwart the most resolute of parties. Prepare yourself for the depths...

New Hamlets, Towers and Huts

Many new locations in Britannia and beyond to discover and explore! More than double the number of locations of the original game means twice as much exploration and discovery. Seek them out, and discover their inhabitants and mysteries.

New World Region

An entire new region of Britannia, waiting to be discovered, mapped and measured. This new region is as large as Britannia itself, and will present challenges which push a parties resolve to the limits.

New Minor and Side Quests

New quests await the avatar, which will lead him across the width and breadth of land in search of clues and artifacts. Follow the quests and he will find aid on his journeys, or ignore them and stay focused on the Quest of the Avatar.

New Items, Artifacts and Loot

New magic items, weapons, rings and more can be found for those who seek. Use them to aid you in your travels, or in your battles. Seek out powerful enemies for the treasures they will render unto thee.

New Magic System

Join in the esoteric realms of magical discovery. Dig deep into the lore of the land, the wisdom of sages, and discover the secret of a new form of magic. But beware, as there can be a price to be paid for those who delve too deep into matters beyond their ken.

Random Encounters

Dozens of random encounters, which range from meetings with pilgrims travelling to shrines, to multi-level ruined cities from ages of yore. Explore them and discover secrets and items which could help on your quests.

Bug Fixes and Improvements

More than 30 bugs fixed, making the Threat of the Trinity the smoothest Quest of the Avatar experience yet. Many small improvements to combat, realism, and balance hone the game. For a full list of fixes and improvements, see below.

Multi-story Towns

Nearly every castle, town, village, hamlet, tower, hut and inn now has multiple stories above and below ground. Explore Brittannia in more than two dimensions. The third dimension is here, and will bring a new...depth, to your Quest of the Avatar experience.

Warriors of Destiny Style Features

Some of the best features of Warriors of Destiny, included with Threat of the Trinity now! Mix multiple batches of reagents, use Active Player to more easily explore complex dungeon rooms, and attack and search in any direction around the player.

A Living Land

The land is alive with creatures, both wild and evil. They lurk where you would think they should, and they spawn from the pits of the earth. The good of Britannia suffer under their predations, and only the Avatar can drive them back.

Complete Feature List

  • New Hamlets and Towers
  • New Dungeons (Crypts)
  • New Caves and Mines
  • New Huts and Wilderness Inns
  • New World Region (Underdeep)
  • New Shops and Merchants
  • New Shipwrights
  • New Major Quests
  • New Minor Quests
  • New Side Quests
  • New Virtue Trackers
  • More than one hundred new Characters
  • Random Encounters
  • New, powerful Artifacts
  • 2nd levels for all Towns
  • Multi-level Castles
  • New magic system
  • New tiles/sprites
  • New mounts
  • Warriors of Destiny style Active Player
  • Warriors of Destiny style reagent mixing
  • Warriors of Destiny style directional search
  • Warriors of Destiny style Clearable Dungeon rooms
  • Warriors of Destiny style ‘Chest Drops’
  • Town Saving
  • Diagonal attacks
  • Fixed/Improved ‘default’ Spells
  • New Spawning rules
  • Variable Battle maps
  • Terrain based combat bonuses
  • Terrain based Camp maps
  • Virtue based NPC reactions
  • Variable NPC personalities
  • Apple II style LOS/Shadowcasting
  • More accurate Port of Apple II original
  • Expanded NPC conversations (reduced scope)
  • Many, many more small additions

Bug Fixes/Improvements

  • Moonphases restored on save
  • All chest trap types working
  • No more infinite Mystic Weaps/Armor
  • Hythloth bug fixed
  • Destard bug fixed
  • Skull of Mondain bugs fixed
  • Missing Lord British dialogue fixed
  • Ship instant repair bug fixed
  • Camping at sea bug fixed
  • Omni-tavern bug fixed
  • Status-Trick fixed
  • Passage of the Moons-Trick fixed
  • Energy Spell Dungeon Drilling-Trick fixed
  • Missing Mana in Inns bug fixed
  • Broken ‘Open’ spell fixed
  • Buggy Ankh and Lord combat sprites fixed
  • Missing Sacrifice gain fixed
  • Attackable chests bug fixed
  • Money Overflow bug fixed
  • Disappearing Horse bug fixed
  • Phantom Pirate ships bug fixed
  • Pre-slept Monsters bug fixed
  • Shop dialogue bugs/errors
  • Inn Encounter bug fixed
  • Talking Chest bug fixed
  • Yes/No Escape bug fixed
  • Edge of World bugs fixed
  • All known dialogue bugs fixed
  • Other Small fixes

Other Highlights

  • Saved games are compatible with vanilla Quest of the Avatar

Credits and Thanks

  • All credit goes to ergonomy-joe for making this possible, thanks to his u4-decompiled
  • Fenyx4 and MrKnitster for beta testing
  • James Van Artsdalen for the conversion to C for Dos
  • George Stepan for the town and world editors
  • Lord British for the greatness that is Quest of the Avatar

Frequently Asked Questions

Do you need the original Ultima IV to play this?

Yes and No. Threat of the Trinity is an addon for the DOS version of Ultima IV Quest of the Avatar. A full installation of the original game will be required to play. However, every file has been modified, and so an original install will be completely overwritten.

Are save games from Ultima IV compatible?

Yes. Save games from the original Ultima IV are fully compatible with Threat of the Trinity. Saves made in Threat of the Trinity are also compatible with the original DOS Ultima IV.

Can this be played on MacOS? Or Windows?

Yes. It can be installed and played anywhere you can run DosBox, or most DOS emulators.

Does Threat of the Trinity change the Quest of the Avatar?

Yes and No. The quests in Threat of the Trinity do not change the main quest, other than to refresh some locations. The quests of Threat of the Trinity compliment and augment Quest of the Avatar, but are not required to be completed to finish the game. Certain game rules have been tweaked or rebalanced, but still operate in the spirite of the original.