Monday, June 1, 2015

Monster Magnification

In D&D, players may find themselves running monster-types as a result of several causes: charm monster, polymorph other, reincarnation, special DM permission, etc. In this post we give rules for a lightweight method to "zoom in" on such characters, providing additional detail and possible advancement, if desired. Note that this assumes the basic OD&D ruleset, OED extrapolations for ability scores (9-12 average, +1 bonus per 3 points over 10), and smoothed-out attack rolls (check d20 + HD + AC 20). To give more detail to monster characters, do this:
  • Take the base number of monster hit dice and call this the “level”.
  • Establish average Strength and Constitution scores for each monster race, as given in the table below (for simplicity, we assume that these are equal for each racial type).
  • For hit dice, roll 1d6 per level, and add the Constitution bonus to the first die only.
  • For attack bonus, take 2/3 the monster level, and add the Strength bonus.
  • For damage by weapon type, ogre-sized weapons do base 1d8 damage, while giant-sized weapons do base 1d10 damage; add the Strength modifier as usual.
  • For individual creatures, roll 3d6 for Strength and Constitution, and add however many points the racial average exceeds 10 (for example: a stone giant adds +12 to both Strength and Constitution rolls). Calculate new hits, attacks, and damage as per the rules above. Roll the standard 3d6 for other abilities. 

Interpretations: The basic idea is that monster types are, by default, unskilled brigands. They lose the Constitution bonus to hit points after the first hit die (as opposed to professional fighters who add it up to 9th level). Their base attack bonus is only 2/3 per level, the same as human thieves, but compensated by their exceptional Strength. They do not earn any special fighter features by default (e.g., weapon specialization).

Weapons: The base damage above (ogre 1d8, giant 1d10) assumes use of a weapon like a club, spear, or crude sword/axe. A light dagger-type weapon will do one die less, while a heavy two-handed weapon is one die greater. A weapon of quality (equal to human weaponsmith skill) is another die greater. Characters can generally use a weapon one size larger than themselves, but must use two hands to do so. Exchanges for equivalence of multiple dice can be made as convenient.

Examples: Giant clubs and spears are usually one-handed, doing base 1d10 damage, but one could use a two-handed version for base 1d12 (or 2d6); whereas a well-made two-handed sword for a fire giant would do 2d8 base damage (all before Strength modifiers). An ogre's club does base 1d8 damage, and can be picked up and used by a human two-handed; but humans cannot use giant-sized weapons. Similarly, an elven dagger can be wielded by a halfling as a short sword, doing the usual 1d4 damage.

Comparisons: See below for a table of comparisons between this system and statistics in the core OD&D books (mostly Vol-2, or Sup-I for the Bugbear and Storm Giant). This shows averages for hit points, attack bonus, and damage, as well as the differences between each system ("error"). Attack bonus is identical for about half of the creatures, and within 1 pip for most of the rest. Average damage is usually within 1 point of OD&D, but adds 2-3 points for some of the giant types. Hit points are nearly identical up through Troll-types, but add a small number of points for giant types (approaching the recommendation in Sup-I that hit dice be 8-sided). I think that this system provides a fairly smooth and flexible interpolation of OD&D, and the differences are "close enough" that players will likely not notice them in play (nor mind if they get a small-grained boost while playing such a creature, on average).

Advancement: Monsters are assumed to start with an effective XP score the same as fighters of the indicated level; they can earn additional experience and gain levels as fighters. Base attack bonus is always 2/3 per level, and hit dice d6; but they do gain Constitution bonuses for extra hit dice (up to 9th), and any special fighter features from advanced levels. In the rare case that one chooses to multiclass as a thief or wizard, all regular rules apply; the creature must have a score of 16 or greater in the prime requisite ability, sacrifice their top level, and then earn XP and levels as normal (maximum one per adventure). However, all thief skills are at –4 in 20 for ogre-sized creatures, –8 for giant-sized; and limits to level advancement may be set by the DM as desired.

Miscellany: One special case here is the Troll – it is the only humanoid-type in the rulebooks noted as using "talons and fangs" instead of artificial weapons; so while the first table above shows a higher-than-official amount of damage, this would only be the case when using weapons (which a Troll is unlikely to do). A second special case is the Storm Giant – above, the Storm Giant is given extra-huge weaponry, increasing another die larger over other giants; i.e., base 1d12 (or 2d6) damage for a simple club, and only usable by lesser giants two-handed.

Finally, compare this system to others such as Stephen Martin's in Dragon #109, May 1986 (which included seven different categories of weapon sizing for AD&D); 3E D&D (which added ability bonuses per die for all monsters, effectively doubling attack bonuses and hit points, and thus breaking compatibilty with earlier editions); or this author's own "Supersize Me!" system published in Fight On! Issue #8, Winter 2010 (which was somewhat more convoluted than the system shown here).


  1. Bookmarked!
    I have been eager for my party to use the life "re-incarnation" stone they found in a previous dungeon.

    1. Excellent! I always give something like that out in my high-level convention games. Would be interested in how that turns out. :-)

  2. I like the monster advancement. Would you have people meet higher level monsters, e.g. the Hobgoblin King?

    1. Right, it at least opens the door to that. I tend to use those things very sparingly, however (no parties of 12th-level goblins roaming around as a rule).

  3. This is great stuff, Delta.
    I would love to see a fallow-up that discusses humanoid leader-types against this framing.