Yesterday's game got me thinking on this again. There's always been a debate, and over the years I've gone back and forth, but for a while I've stuck with these: Battle Axe: two handed 7.5 lbs, 4' long Morning star; two handed 12.5 lbs, 4' long Horseman's X: one handed: horseman's mace is 5 lbs., 18" Footman's X: two handed: a footman's mace is 10 pounds, 30" Staff: two handed: 6' - 8' long
Staves and battle axes are specifically called out as two handed in basic, but there is only mace, etc. Not footman's/horseman's. Footman's maces and battle axes are probably the biggest issues. For most of the time I've played I've allowed them to be 1 handed, and most other DMs do too. For comparison your average baseball bat is 34", 2.25 pounds. A battle axe is about 3 x as heavy and a foot+ longer. A footman's mace is like a 10 lbs baseball bat.
am I overthinking it? Should I just 'it's fantasy' and go with it? I think Mythus has strength guidelines for 1 handed vs. 2.
Everything you wrote is logical and makes sense, but... In practice I go with the 'it's fantasy' approach. I've been allowing player characters to use footman's mace with shield for decades now, so I'm not going to change now. Also, I've allowed fighters to use battle axe with shield which is probably a mistake. I used to think the main difference between battle axe and hand axe was that battle axe was melee only but hand axe could also be thrown. Not a big deal since battle axe does about same damage as a long sword, but I should probably give a bonus to those who use the battle axe two-handed similar to the bastard sword rules. The battle axe is slightly longer and heavier than a long sword, but the damage is inferior to large creatures. The only ones I really enforce as two handed are the pole arms and two handed swords, and the quarterstaff (since that is obvious from Robin Hood and Kung Fu movies), and I don't allow ridiculous combinations like gnomes with bastard swords and that kind of stuff. It would be easy to go down the rabbit hole of simulated realism and come up with a matrix to compare weapon weight and length relative to character size and strength to determine what is one or two handed. I wouldn't have a problem with that if the DM put in the work doing the research. I'm always a fan of anyone who can bring historically accurate medieval details into the game.
Something else I tend to go by are miniatures. Most miniatures depict the mace as a one-handed weapon. Battle axes get depicted both ways.
This is an old debate but I think most things are one handed unless painfully obvious is the rule.The Conan big axe was a fascination with my brother. One of the official 1983 TSR minis had the orc chieftain holding a big axe one handed.
The Golden Mace of Hercules from Marvel Comics influenced my belief that the mace is a one-handed weapon prior to even playing D&D. In the Baldur's Gate video game, the footman's mace and footman's flail were one-handed weapons.
According to the Wiki, the name mace comes from French "masse" which means large hammer. The first maces are considered to be Paleolithic clubs with spikes of flint or obsidian added to the head. Technically that should make them morning stars if one goes by the distinction that non-spiked ball is a mace and the addition of spikes makes it a morning star. But there doesn't seem to be a clear distinction as flanges, spikes and different shapes were used throughout history with a lot of the innovations intended to help penetrate armor. The horseman's mace -- as well as the other horseman's weapons -- should be longer.
If I were going to modify the system, I would rather add than take away. I would consider the existing footman's mace one-handed and doing the damage listed, but if used two handed could do more damage. The same with the other footman's weapons and the battle axe. Also, there could be a two-handed mace/morning star/flail that is longer and heavier and can only be wielded by creatures with enough height and strength to do so (man-sized with 16+ strength for example can wield it two handed). That eventually gets you up the scale into giant-sized weapons that are too big to use no matter how strong the character is, unless some enlarge or growth magic is used (King Snurre's sword, Queen Frupy's scepter, etc.).
The flail Wiki states: "The chief tactical virtue of the flail was its capacity to strike around a defender's shield or parry. Its chief liability was a lack of precision and the difficulty of using it in close combat, or closely ranked formations." That would be interesting to give the flail the ability to ignore shields. I wish EGG was still alive to discuss this topic since clearly he was open to the idea of different weapons having different characteristics with a basis in historical usage.