Cheating in Ultima V

Ultima V has fewer cheats than the later Ultimas. Yet there are some bugs that can be exploited.

Maxing Stats
Depending on your karma will determine your loss of exp. Hit CTRL K to see your karma. The higher your karma the fewer exp you lose when you die. When you die, you lose 50 exp.

So get your characters to around 220 experience, camp until Lord British appears to set everyone's level to 3 and then die. You will go back to level 2 but you will NOT lose the stats (INT/STR/DEX). Repeat the process until you reach 30-30-30.

The results are amazing: your party will be overwhelming. I think DEX is the most important attribute, as you will get to take several turns before your opponents move and also you will never miss an attack.

Castle Britannia's Bottomless Vault
At the bottom of Lord British's Castle is a magically locked door, beyond which can be found three chests that are always filled with goodies. You can find basically anything in these chests, including the valuable Magic Throwing Axe. These chests respawn if you go up-and-down stairs, but that also relocks the magical door. The best way to revisit the chests without having to waste a Skull Key every time is to sleep for 1 hour. There are 2 beds on this level of the Castle, so make use of them when they're not occupied!

This does cause you to lose karma, about 6 points each time you empty the stash.

Infinite Skull Keys
Kristi in Serpent's Hold will sell you 5 Skull Keys for 100 gold. So long as she never asks you for your name (prompted by saying 'visitors' to her), you can keep asking her to sell you more keys.

Invisibility Rings
Ophidian Dragon said that invisibility rings seem to have the curious effect of reducing a monster's HP to near zero, so you should even be able to kill dragons in one hit!

This works because the game needs to make the enemy leave the field if all your party is invisible. You still can't kill Lord Blackthorne this way, though.

Invisible rings will randomly vanish when you use them, so you can't use them in every battle.

Easy XP and Loot
In dungeons, if you leave one enemy alive in a room, all the enemies will have respawned when you return. Couple this trick with the Invisibility Ring trick above, find a room full of dragons, and you should amass XP and treasure quite quickly.

There is also a dungeon room in Wrong or Covetous which has a monster chained to the wall. You can kill all monsters but that one, which cannot attack you. It's filled with Wisps, so wear the crown and use a halberd-weapon to attack it inside the walls where they will be stuck.

Infinite Reagents
Similar to the C64 cheat below, if your reagent count went to -1, it would be set to 99. So if you got all your reagents to 99 and always mixed everything in batches of 50, you could easily mix all spells without ever worrying about reagents.

Land Of The Wrong Disk
When the player is wandering across Britannia or the Underworld, the game loads a few screens worth of the map at a time, but doesn't check whether the correct disk in the drive. Having the opposing disk (Britannia if in the Underworld & vice-versa) in its place will load the equivalent part of the its map instead of the correct one; the other disks fill the area with random tiles they contain, such as manacles on the Dungeon disk or a harpsichord from Castle disk. Both methods can be used to circumvent water, high mountain peaks, or other obstacles -- assuming what they load in its place isn't equally impassable -- which can be invaluable when trying to reach special locations or quest items.

More Reagents
In the C64 version, if you have between 11 and 15 of some reagents, then mix a spell using only those reagents, and mix 16 of the spell. You should get 16 of the spell you mixed and 90+ of the reagents.

More Food
Clever Avatars can use a bug in the C64 port.

In the pub of Empath Abbey are provisions where the programmers have forgotten to apply a "other people's stuff"-tag. Meaning: you can take them and it's not stealing. Climbing then up and and down the ladder exploits another bug, as the food will re-appear. This means without paying or karma-loss you can get lots of food.

Cheap Way to the Underworld
There is a very easy way to enter the Underworld, thanks to sloppy programming.

After entering the wilderness of Britannia, replace the Britannia-disk with the Underworld-disk. At first nothing will happen. However, wait until you are drawn into a battle. After winning or fleeing, you'll find yourself at the same coordinates in the Underworld. Of course this can also mean being stuck in a mountain, so try to figure out, where in the Undeworld you could appear.

The same trick can be used to return to the surface, by again swapping the disks and getting drawn into a battle.

POKE-cheating
On a real C64 with a cheat module like the Action Replay VI, or on an emulator with a cheat function, the following POKE-codes can be used during the game. Note that if there are two POKEs for the same effect, it means that both have to be entered for the cheat to work.