Size-based combat modifiers in D&D

(Here’s a post I started a long time ago. My group has started up another 3e campaign, though, so time to finish it up and publish it.)

In 3e D&D, a “small” creature gets a +1 to attack rolls (which makes it easier for them to hurt others in combat) and a +1 to Armor Class (which makes them harder to be hurt in combat). Conversely, a “large” creature gets a -1 to attack rolls (which makes it harder for them to hurt others in combat) and a -1 to Armor Class (which makes them easier to be hurt in combat). Bigger and smaller creatures have larger and smaller modifiers in the same vein.

Here is the relevant section from the d20 SRD

The problem here is that 3e often falls for a fundamental mistake about how the underlying combat system works. The attack roll was formerly called a “to hit” roll, but if you analyze the entire system, you see that thinking of this roll as actually determining whether an attack made contact doesn’t really make sense. Attack rolls, armor class, damage rolls, and hit points really have to be treated together as an abstract system.

If you say that because larger creatures are easy to hit than smaller creatures and thus give the larger creature a penalty to Armor Class, you haven’t really represented that larger creatures are easier to hit. What you’ve done is made the larger creature less effective in combat. The D&D combat system doesn’t answer the question of whether an attack hits. It answers the question of how effective each combatant is.

You can say that adjustments to constitution scores, hit dice, and hit points make up the difference. In truth, however, they really don’t.

It might work, however, to reverse the modifiers. Giving small creatures a penalty to attack rolls and AC would make them less effective in combat, which is what I would expect the general rule to be. Giving large creatures a bonus to attack rolls and AC would make them more effective in combat, which—again—is what I would expect the general rule to be.

Highlights at dndclassics.com

Here are some items on dndclassics.com that I thought were worth highlighting.

D&D Basic Set Rulebook (Moldvay edit): I may be biased. This was my first role-playing game purchase. I still think, however, that this is the best version of the game published under its own name. While it is heavily rooted in the original game; it is cleaned up, organized, and communicates more clearly than its predecessors. It’s compatible enough with all other TSR-era editions of D&D and AD&D that you can cherry pick bits from them when and if you want to expand on it.

This book only covers levels 1 to 3. With its companion Expert Set, you have a game that goes to level 14 and beyond. As I’m writing this, though, the Expert Set Rulebook is not yet available on dndclassics.com.

B2 The Keep on the Borderlands: This adventure came in the box set with the Basic Set Rulebook above. In some ways, I consider this as much part of the “core rules” as the Rulebook itself. It gives some practical advice and examples for Dungeon Masters.

HR1–7 The “historical reference” series: These are for me perhaps the best things to come out of the AD&D 2nd edition era. I’ve always liked a bit of history in my games. I think game books about history in some ways do a better job of giving you a feel for what historical periods were like than most history texts. Because they are more concerns with playing in that world rather than describing historically significant events. Here are the links:

• A bundle of all seven
• HR1 Vikings
• HR2 Charlemagne’s Paladins
• HR3 Celts
• HR4 A Mighty Fortress
• HR5 The Glory of Rome
• HR6 Age of Heroes
• HR7 The Crusades

Rules Compendium (3e): (Not to be confused with the Rules Cyclopedia, which I hope will appear on dndclassics.com in the future.) While the Wizards-era 3rd edition isn’t my favorite edition of the game; I do like it, and I do play it. So, I’m curious about a book that purports to bring the most important rules of that game together along with correcting errata. Although, I’m not sure it would be any more useful than the Hypertext d20 SRD.

Unearthed Arcana (3e): (Not to be confused with the first edition AD&D Unearthed Arcana which is not yet available through dndclassics.com.) This book may be the most “old school” book of the Wizards-era 3rd edition. Because it gives you all sorts of tools for modifying the game and making it your own. All the rules are also open content and available in the Hypertext d20 SRD. The book itself, however, also includes some helpful commentary.

Edit: ...and I have now purchased all the items on this list.

Classic D&D prayer beads

In my classic D&D campaigns, the question always comes up whether I will allow clerics (a.k.a. crusaders) to swap out memorized spells for “cure” spells as in the Spontaneous Casting rule from the d20 SRD. I have a hard time deciding.

Then, I came across this, which I find much more interesting. From AC 4: The Book of Marvelous Magic (1984) by Frank Mentzer and Gary Gygax, p. 16:

Prayer Bead: This valuable item allows a cleric to exchange one known spell (not yet cast) for another if both are of the same spell level. For example, if the cleric knows detect magic but needs cure light wounds, the cleric may use the bead to forget detect magic and gain knowledge of cure light wounds. The new spell may be cast as soon as desired. The cleric need not be fully rested to use the bead. After changing one spell, the bead disintegrates.

(For those not familiar with classic D&D jargon, “knows” means “prepared” and “forget” is equivalent to “lose” in the Spontaneous Casting rule.)

If these prayer beads were as available as holy water or—in some campaigns—healing potions, then it’s an interesting resource management mechanic. (Assuming you find resource management mechanics interesting. And classic D&D might be the wrong game if you don’t.) And it is more flexible too.

Trivia: In the original text, the name of the second spell was styled—both times—“cure light wounds”. I have assumed this was a mistake and put “cure” in italics as well.