Day 26 of the 30-day D&D Challenge asks for my favorite non-magical item.
My go-to build for a fighter is usually some kind of steppe nomad warrior, using bow and scimitar. Thus the non-magic item I find most useful is the Strength-adjusted composite shortbow, for the added Strength damage bonus. I believe the rules for this kind of bow were introduced in AD&D, but our DM Augs allowed it for my character in a BECMI game. Combined with the Weapon Mastery rules, it made for a really deadly archer.
I’ve always been fascinated with bows and archery. Researching the topic led me to finding out that the steppe peoples did not all practice archery the same way, so their bows and arrows, while made of the same three basic materials – wood, horn and sinew – actually had different designs. Some were made for greater hitting power at the expense of range, some were made for distance shooting like the Turkish bow and flight arrow, and some were made for rapid shooting at the expense of power and range. Interestingly, accuracy did not seem to be a priority – perhaps because it was a given that a decent bow was accurate enough in the hands of a practiced archer, or because much of military archery revolved around getting as many arrows into an area as possible rather than hitting individual targets.
Applying this to your D&D setting, you could have different races or cultures making more varieties of bows than just the long, short, and composite types standard to the game. Maybe the elves don’t have very powerful bows, but the ones they have are so finely made that they’re more accurate than normal. Steppe nomads, and perhaps halflings, tend to like bows than can loose a lot of arrows in a short time – add +1 to the ROF. Or maybe more – take a look at this video!
And you can have a human culture modeled after the medieval English, who shoot big yew bows that pack more punch than normal.