In the dungeon, there are few things worse than generic +number weapons/armor. “Oh boy! I got a +1 shield” said no one ever. I know that statement seems ridiculous, given the things that can happen in a dungeon. Your character can stabbed, bludgeoned, poisoned, sacrificed to an evil god, disintegrated, eaten alive, hacked to bits, turned into an undead monstrosity, petrified, etc.
So why would finding a +1 shield be so bad? It is a magic item that may help prevent the above fates, right? That is true, but the D&D experience…should be magical! Interesting! Finding a magical item should not be like upgrading the RAM in your computer…just exchanging a smaller number for a larger number. Finding a magic item should inspire awe, wonder, disgust, or some sort of emotion in the player. D&D should more Sword & Sorcery (Conan the Barbarian and Jirel of Joiry) than the higher fantasy found in the Forgotten Realms. Magic should be weird and wonderful, not mundane and merely mechanical. A character with a magic weapon should be powerful, but maybe a little afraid of the power in their hands.
I understand that there is a mathematical need for +number equipment in order protect against more powerful threats and also to damage those threats. I am not suggesting that the math needs to be completely reworked so that +number weapons/armors do not exist. What I am suggested that the +number is only part of the item. A +2 dagger that is constantly emitting noxious fumes from a never-ending font of foulness hidden in some inter-dimension space within the hilt is something interesting. On a hit, this dagger gives the enemy a fast-acting and nasty-sounding disease (like the Red Cough) unless they make a save. Give the dagger a name or possibly a little history and you have an item that your players will want to get their hands on. Imagine this:
VALERIA, the party’s rogue, stabs the GNOLL in the back with PLAGUEBRINGER, THE DAGGER THAT SINGLE-HANDEDLY DESTORYED THE MENGVORIAN EMPIRE. The GNOLL doubles over and begins coughing. A foul red liquid that is not just blood spews forth from the GNOLL’s mouth, splashing against the shield of ROWGDAR THE JUST.
“Roll a save versus disease or you will catch the Red Cough too,” the GM says to the player playing ROWGDAR THE JUST.
One thing (among many) that 5E did better than 3.X is that it reduced the need for characters to be decked out in magic items (that often added mere mechanical bonuses) to handle higher level threats. With the attunement system in 5E, a character can only be attuned to three magic items at a time. Now, not all magic items require attunement, but most of the interesting ones do. Therefore, the player has to make difficult choices regarding what items they keep.*
What I propose is to find a way to give generic +number weapons/armor at least one minor interesting ability so that players must make a real choice when finding a new magic item, instead of simply seeing a +2 attached to the item instead of +1 and throwing away the +1 item. Is a an additional +1 to hit/damage/AC bonus worth giving up the ability from the old item? Is the ability on the new item better? The same? Worse? Even if the ability is not mechanically powerful, it should have the potential for something interesting to happen.
Remember in The Hobbit the swords Glamdring and Orcirst? The orcs and goblins certainly did! Even if they just a +1 swords, +4 vs orcs and goblins, the fear/hate of the orcs and goblins when they saw the weapons would be interesting at the table. In your game, imagine trying to negotiate with some goblins for safe passage through their territory…and they notice that one of the characters has Glamdring strapped to your side. Whoops!
* In order to maintain higher level monsters with lots of abilities at their disposal, I suspect that Wizards of the Coast increased the power level of characters so that players did not need to be wearing 17 different magic items in order to effectively fight higher level threats. Let’s fact is, replacing a +2 headband of intellect with a +4 headband of intellect does not really stir the blood, does it?