D&D 5E Magic weapons granting tremorsense, rather than shedding light: balanced?

[Deset Gled]

I have to wonder, after all, why dwarves or drow would craft magic weapons that shed small amounts of light. They have darkvision so it's of very little help to them,

Color. Darkvision is black and white.

Distance. Darkvision has limited range.

Brightness. In 5e, darkvision works better in dim light.

And, ignoring all that, they might not have a choice. Sometimes magic glows whether you want it to or not.

 

[Lanefan]

This idea seems fine to me pretty much straight up, and a neat twist.

The only limit I might put on it would be that it wouldn't pick up walking creatures of less than, say, 100 lbs weight. It might also have trouble picking up tremors if the ground is covered with deep snow or sand. It'd pick up burrowing creatures of any size, though, while useless against fliers or swimmers.

 

[niklinna]

 

[Stormonu]

If it was about 10 feet tremorsense, I'd probably do it. If it got troublesome, might require the use of a bonus action (or action, depending) to focus on the "thrumming" to pinpoint something.

 

[el-remmen]

You mean, the curse is that you are struck blind, in general, and the tremorsense only happens when you are wielding the weapon?

Hmm, that is not what I meant - but I can see that working depending on the narrative and makes more sense as a drawback than what I was suggesting.

 

[Cap'n Kobold]

How about a cursed weapon that grants tremorsense but also blinds the attuned wielder?

Would that mean that all attacks by it are at disadvantage?

 

[Quartz]

How about a cursed weapon that grants tremorsense but also blinds the attuned wielder?

That doesn't sound like fun.

 

[Blue]

For a character like a scouting rogue, tremorsense is much more useful than light. Light gives yourself away. And if you need light, it's not an either/or - it's fairly easy to light something (or unhood an already lit lantern) and have both.

 

[Whizbang Dustyboots]

Would that mean that all attacks by it are at disadvantage?

Not with tremorsense active. That might have to be explicitly stated as an exception to normal blindness rules, though.

 

[Paul Farquhar]

This feels like it's roughly balanced, since generally speaking, having a light source is more useful. (It's hard to read the inscriptions in an underground tomb with tremorsense.) But I haven't ever seen this in play, as I recall, so maybe I'm off here.

Would you allow this substitution on a weapon, DMs?

What do you mean by balanced? 5e isn't balanced around magic items.

What do you mean by "allow substitution"? Generally, once they are found, the properties of a magic item are fixed.

Tremorsense is undoubtably more powerful than light, but I see no reason not to have tremorsense granting magic items in the game.