# How do I determine this monster's HP if I'm only given its HD?

The Hungry Coffin homebrew monster from Goblin Punch states the following:

Hungry Coffin
HD 6 AC 14 Slam 2d6 or 2d8 Swallow 1d6 + swallow
Fly 9 Int 5 Morale 12

It says the Hungry Coffin has "HD 6". This doesn't help me at all, because I still don't know what its average HP is, or how to roll its HP. How do I figure this out? Thanks!

• it's a homebrew from a blog called Goblin Punch. Just using it because I had that page open at the time. Jul 29 '15 at 0:17
• the default in adnd games for monster dive tends to be an eight sided dice. So for each HD roll a d8 :) problem solved Sep 25 '15 at 11:11

Hit dice for monsters in both editions of AD&D are almost always d8s, so it's normal for monster stats to say things like “6 HD”, “3 HD + 4”, or “½ HD” with no further explanation given.

From the Monster Manual introduction where how to read statistics is explained:

HIT DICE indicates the parameters of the number of hit points a creature can withstand before being killed. Unless stated otherwise, hit dice are 8-sided (1–8 hit points).

Most monster stats only list HD, since that's sufficient to determine hit points (and economical of page count). Actual hit points are rarely listed except when an adventure indicates how many a specific individual creatures has, and even then it’s common to list only HD, with HP to be determined when needed.

If you come across any HD stats with a plus, that's covered in the same passage, where it explains that it's added once to the sum of the dice.

Although AD&D does have a deserved reputation for being poorly organised, the books are fairly reliable at explaining core concepts like this. When in doubt about monsters, consult the Monster Manual and you'll be good.

Aside, that “AC 14” is ascending Armour Class which will have to be converted to descending AC (lower is better) to work in AD&D’s rules — assuming you're not using ascending AC house rules. To convert ascending AC to AD&D’s descending AC, just subtract it from 20; in this case 20 − 14 is 6, for a descending AC 6.

There's a document on Goblin Punch (You can find it here) that explains the hit die for monsters on the site is a d8:

Monsters have 1 HD for every level they possess. This is a d8 hit die, so a level 3 monster has 3d8 HP.

• Sounds like this is a Goblin Punch thing and in other cases HD alone is meaningless for determining HP, is that right? Jul 29 '15 at 1:40
• @doppelgreener I've got a strange feeling that AD&D had the convention that if the HD size of a monster wasn't specified in its description, then it defaulted to being a d6 or d8... but I can't remember which, and don't have my books on hand to check. Jul 29 '15 at 1:56
• Page 5, 1 edition AD&D MM, states under Hit Dice exactly what SSD has in his answer. Jul 29 '15 at 12:43