Strength is Size

One thing I tend to do in D&D-esque games is treat the Strength attribute as indicating size as well. (Other games, such as Chaosium’s Basic Role Playing and its kin have a separate Size attribute.) It seems to me, though, that there’s a bunch of pretty good arguments that the two are at least highly correlated, if not one and the same.

In most combat sports, from boxing and wrestling to taekwondo, as well as sheer strength-based sports like weight lifting, competitors are divided into weight classes for both health and safety reasons as well as to make the competitions more fair (and interesting). The average winner of the World’s Strongest Man competition stands 6′ 4″ and weighs in at 390 pounds!

Moreover, at least in the earliest editions of D&D starting with Supplement I Greyhawk, the two biggest mechanical differences from exceptionally high or low strength scores are to-hit, damage, and carrying capacity. To-hit I think makes perfect sense as reach, which is a huge factor in hand-to-hand combat, as does damage as function of mass (again thinking about weight classes in combat sports). Carrying capacity is a little less clear, in that the additional weight of your body seems to count against your maximum carrying capacity, at least over distances¹, but since the bonuses tend to be linear while body weight increases exponentially, I call it good enough for D&D.

As a quick approximation for human, you can look up Strength in the following chart. I leave it as an exercise for the reader to apply adjustments for non-humans, and of course you might decide that any particular character is a bit bigger or smaller than the chart indicates. ² Or you might decide (as my long-time Friday night GM did) to just roll size separately on 3d6.

	SD		Male			Female
		Height	Height	Weight	Height	Height	Weight
Strength		5′ 9″	69.30	169	5′ 4″	64.10	135
SD	2.96	2.92	2.92	27	2.75	2.75	24
3	-2.53	5′ 2″	61.90	101	4′ 9″	57.13	73
4	-2.20	5′ 3″	62.89	110	4′ 10″	58.06	82
5	-1.86	5′ 4″	63.87	119	4′ 11″	58.99	90
6	-1.52	5′ 5″	64.86	128	4′ 0″	59.92	98
7	-1.18	5′ 6″	65.85	137	5′ 1″	60.85	106
8	-0.84	5′ 7″	66.83	146	5′ 2″	61.78	115
9	-0.51	5′ 8″	67.82	155	5′ 3″	62.71	123
10	-0.17	5′ 9″	69.30	169	5′ 4″	64.10	135
11	0.17	5′ 10″	69.79	173	5′ 5″	64.56	139
12	0.51	5′ 11″	70.78	182	5′ 5″	65.49	148
13	0.84	5′ 0″	71.77	191	5′ 6″	66.42	156
14	1.18	6′ 1″	72.75	200	5′ 7″	67.35	164
15	1.52	6′ 2″	73.74	209	5′ 8″	68.28	172
16	1.86	6′ 3″	74.73	218	5′ 9″	69.21	181
17	2.20	6′ 4″	75.71	227	5′ 10″	70.14	189
18	2.53	6′ 5″	76.70	236	5′ 11″	71.07	197

1. Backpack Weight and the Scaling of the Human Frame
2. Distribution of Body Weight and Height . It’s actually pretty hard to look up data on raw weights instead of BMI, and I’m not particularly confident that the standard deviations in weights correlate exactly with standard deviations in height as the chart would indicate, but whaddaya want for nothing?