So What Is Thunderhall?

Thunderhall is located in the kingdom of Magremore, in the northern badlands known as The Hauts, on the border between Malihaut and Stromhaut. Thunderhall was a castle. Now it is the sunken ruin of a castle. Thunderhall, for all of its glory, was built on a sinkhole, the land beneath it having given way due in part to the underground waterways over which it stood and also in part to the Lord Untergehn’s dungeons which were under constant construction, obsessed as he was with expanding farther and farther down. It is known that Untergehn extracted great wealth from the earth beneath his castle, but the rumors say that the true extent of his treasures is far greater. Six months after the castle’s collapse Lord Abakmer led an expedition of more than fifty men into the sunken ruins. They constructed a kind of bridge down which they marched with their beasts of burden, expecting to return with the wealth of Thundehall. But no one ever heard from Abakmer or his men again, and the wooden parts of their construction were found completely burned away. Now and again a party of adventurers hoping to strike it rich venture out to Thunderhall but few if any have returned.

URFAD: Player Character Races

Dwarf
Classes: Fighter (level 8), Thief (level 6).
Restrictions and Benefits:

1. +4 to magic-based saves. +2 to find traps. +1 to hear noise. 
2. Note sloping passages, unstable or shifting walls, new construction, etc., while exploring, and has a 2-in-6 passive check for traps while exploring. 
3. Take only half damage from ogres, trolls, and giants. 
4. Dwarfs will typically speak Dwarfish, Common, Gnomish, Goblin, and Kobold.

Elf
Classes: Fighter (level 6), Magic-User (level 8), Thief (level 9), or combination of any two.
Restrictions and Benefits:

1. Elf magic-users and thieves may not have more than 6 HD.
2. When elves multi-class, the total levels gained between their two classes may not exceed 10. Elves must adhere to class restrictions, but those that combine magic-user and fighter may cast spells in leather or any magical armor and use swords and bows without penalty. XP is divided half to each class until second level is reached in both classes; after that, the two classes may never be equal so players must decide which class XP will be allotted to, alternating as needed (i.e., one class must be raised to level 4 before the other can be raised to level 3).
3. First-level elves may progress faster in one class than the other since the XP bonuses (if applicable) are applied after the XP is split between the two classes and each prime requisite is considered separately. Likewise, when later allotting XP to one class or the other, use only that class’s prime requisite to determine if a bonus applies or not. 
4. +2 to find secret doors. +2 to hide in wild. +1 to hear noise. +1 to move silently (leather only). 
5. Elves have a 2-in-6 chance (passive check) of sensing secret doors and passages while exploring.
6. Unaffected by ghoul paralysis. 
7. Elves will typically speak Common, Elvish, Hobgoblin, Gnollish, and Orcish.

Hobbit
Classes: Fighter (level 4), Thief (level 6)
Restrictions and Benefits:

1. Hobbit thieves may not have more than 4 HD.
2. +4 to magic-based saves. +2 to missile attacks. +2 to hide in wild or shadows (leather only). +1 to hear noise. +1 to move silently (leather only).
3. Hobbits use small or customized weapons: bow, dagger, hand axe, mace, sling, spear, sword, and war hammer.
4. Hobbits will typically speak Common and Hobbit.

Human

Classes: Any class to max level (10).

URFAD: Changing Classes

Human characters may change classes prior to attaining level 6 of their original class, provided they have a score of 12+ in the prime requisite of the new class. The benefits of their original class are generally retained (i.e., magic-user spells or thief skills) so long as the original restrictions continue to be followed. The attack bonus and HD from the original class remain until those values are surpassed in the new class. When characters achieve the same level as they were in their initial class, then they lose one level from their initial class. The levels of each class combined may not exceed ten. Clerics who change class lose all special abilities except repel undead. Clerics may not become magic-users, and magic-users may not become clerics.

URFAD: Hit Dice/Hit Points

1. Hit Dice is always a d6. At first level, count a 1 or 2 as a 3, and a 3 as a 4.
2. 0 HP means death.
3. Characters heal 1 + CON hit points per two full days of rest. Additional healing is possible through potions (2–7 HP per dose unless stated otherwise) and spells.