I've been playing this game for an embarrassingly long time, and I am just realizing that I have absolutely no idea about the combat mechanics. Sure, a long sword has a 15 attack value, but what does that actually mean in game terms? It seems to correspond to damage, but I'm not sure sometimes.

Similarly and MOST frustratingly, my characters seem to take the same damage no matter what armor they are wearing. I've tested this with heavy armor and no armor. They always take about the same damage and seem to get hit just as often. What does armor do for me? Does it reduce incoming damage? Make it harder for enemies to hit? Is this a bug?

Does anyone know?

I believe the way it works is as follows:
* Hit chance for most weapons is based on the attacker's Dexterity. For blunt weapons, Strength is used instead. 30 in the stat guarantees that the attack hits.
* Evasion is based on the target's Dexterity. Note, however, that someone with 30 in the attacking stat will always hit, regardless of the target's Dexterity.
* Damage from the weapon is anywhere from 1 to the weapon's power. So, 15 attack means 1-15 damage, before taking into account armor.
* Armor subtracts from the damage a random amount from 1 to the armor's power. If this reduces the damage to 0 or less, then the game tells you that the target was "grazed", and the target's HP doesn't change, (Note that this is not a miss, but rather a 0 damage hit.)

Some special cases:
* If a ranged attack misses, it may hit a different target instead. If this happens, the unintended target is guaranteed to be hot.
* Spells work similarly, but use Intelligence on both sides to determine success rate. (30 Intelligence is *really* powerful, as it ensures that powerful spells like Charm and Kill always work.) Armor does not mitigate spell damage.
* Heal heals 1-30 HP. (Yes, this means you can get unlucky and have it heal only 1 HP for all the trouble you went through to cast the spell.) Great Heal is a full heal, but in Ultima 5 can't be used during combat.
* Ultima 6's combat mechanics are similar. One major difference is that physical attacks (but not spells) are significantly less accurate, so 30 doesn't even come close to guaranteeing a hit. (Also, when casting a spell in Ultima 6, it will take longer for your next turn to come around.)

Thank you! This has been driving me nuts. How did you learn this wisdom? I couldn't find it, even after poring over guides, wikis, ancient hint books, etc...

The armor value is randomized??? What sadist dreamt that up? It explains everything, though.

One key source is the Ultima 6 design document, which I think may be available in the Martian Dreams extras. (Martian Dreams is free on GOG, and it's one of the two side games that uses the Ultima 6 engine.) The design document references how Ultima 5 worked, and how they wanted to change things for Ultima 6 (though it appears to have been before the reduction in physical accuracy).

Also, observation about how attacks never fail to hit once the stat reaches 30. (This is especially noticeable with spells. At 30 Intelligence, Charm is *really* good; it reliably works, doesn't wear off, and enemies will sometimes attack the charmed enemy instead of you (oh, and you control the charmed enemy); it's one thing that's allowed me to solo this game.)

WHOA! Thanks for that information dump! That was awesome. I had no idea that a higher AC/DMG value for armor/weapons essentially just means a higher value die. But it explains so much about combat now.

Question, where exactly is this Ultima 6 design document? I'd love to figure out what the mechanics are behind Ultima 6. I looked at the Martian Dreams design documents available via GOG, but I can't seem to find the document you are referencing. The closest might be the object design document? But even that doesn't seem to provide the kind of information you wrote above.

I don't remember, but I think it didn't have all the details. I do remember seeing the specific bit about missed ranged attacks being guaranteed to hit in Ultima 5, and them wanting to change it for 6 to actually require an attack roll against the new target.

Object design, though, is interesting, and you can use Ultima 6's Iolo Cheat to experiment; it allows you to create arbitrary objects with the quality and quantity that you specify (anywhere from 0 to 255 IIRC).

By the way, did you know that, in Ultima 6, enchanted staves are containers, and you can get them to dump their charges on the ground by animating them? (Unfortunately, you can't pick them up or otherwise interact with them.)