AD&D TO MYTHUS PRIME:
(The conversions roughed out below assume familiarity with both rules systems)
To generate the new HP's TRAITS, use the following guidelines:
Ability Score(s) TRAIT
(Int x 3) + 6 Mental
Str+Dex+Con + 6 Physical
((Wis + Cha) x 0.5 x 3) + 6 Spiritual
(The reason for the +6 is to allow an Intelligence of 18 to equal a Mental TRAIT of 60, the maximum for a starting character; if you are translating a non-starting character (i.e. an experienced adventurer), you might consider dropping the +6 and tailoring the TRAITS through judicious use of AP's, as below)
Convert the Class into a Vocation, and re-build the skills as per a starting HP. It might be best to use similar skills to NWP's chosen when selecting the bonus K/S areas. Suggested conversions:
AD&D Class Mythus Prime Vocation
(1) Take Priestcraeft and Religion as bonus K/S Areas to preserve feel and powers
(2) Take Botany, Animal Handling, and Subterranean AErth as bonus K/S Areas
(3) Take Botany, Survival, and Nature Attunement as bonus K/S Areas
(4) These are very loose translations, as the magic systems are not all that terribly compatible; as an alternate, one can use the Mage Vocation, already posted to the list (and a determined JM can of course assign schools (ex grey for an illusionist) to match specialists)
Assign 10 AP's for every level beyond 1st that the character has advanced, dividing them up as appropriate for the character. Equipment translates normally, but magic items are much harder to handle (JM discretion, but magical weapons typically recieve a +5% bonus to attacks for each plus, and a +1 to damage for each plus).
To determine Physical TRAIT, take the Hit Dice and multiply by 32, adjust as seems appropriate (for instance, an Orc probably should have around a 40 instead of a 32 for average), then adjust up or down by 4 for each plus or minus (ex, a goblin (HD 1-1) would have a P TRAIT of 28). Mental TRAIT can be generated by cross-referencing the intelligence level with the chart at the beginning of the Monster Manual/Monstrous Compendium and treating as above.
Armor absorption should be handled as 2 points per point of AC beyond 10 (i.e. an AC of 5 would grant 8 points of absorption, or an AC of 0 would grant 18 points of absorption). Of course, use armor ratings if normal armor is indicated.
Damage translates loosely by comparing the equivalent damage in weapons. So, 1d10 (a two-handed sword) of bite damage can be translated as 6D6, or a 1d8 translates as 4D6 (long sword).
Other abilities (magic, special attacks) should be determined individually.
I have used these guidelines successfully to run several DUNGEON adventures in Mythus Prime, and they've worked well so far.
Conversion written by Mike Phillips (firstname.lastname@example.org)