Military Technology
Many “classic” medieval weapons have not come into use. The English longbow as a weapon of war is still in the future. The crossbow is still used mostly for hunting, and is hand drawn and weak. Neither bows not crossbows are commonly made of composite in Europe — only wood.
The halberd, pike and morningstar, along with other weapons made popular in the High Middle Ages and Renaissance, do not exist as we know them. The most popular weapons are the axe and spear, since they are easy to make (blacksmiths make them in peacetime as tools and for hunting, respectively). Swords are somewhat more rare, and are more cherished — they are found in the hands of full-time warriors. Peasants use various farming tools converted into weapons when they have to fight.
Armor is much lighter in this era than in the D&D setting. Mail armor is the heaviest armor in general use. Even lighter plate armor is a thing of the future. The large, round shield of the Viking is still used by infantry, but the large “kite” shield (flat on top, pointed on the bottom) has been developed for men who fight from horseback. Gunpowder does exist in China, but has not spread, not even to the Moslem world. There are no cannons, much less muskets or arquebuses.