Hey everyone, looking for some feedback for use of cantrips in my campaign. My group is at the point where they rescued a small village a good distance from any large towns. The wizard wants to build up and make a small town out of it and perhaps start a guild. I am fine with all of this, and i did some research on how long it takes to fell trees and build structures and such. 

My issue is the wizard wants to assist in the building of their small town, he has taken a feat to be skilled in wood working and has fabricate. That is cool, the issue is from his use of cantrips like Mold earth. Fabricate is a limited use, although by game rules Mold earth can move a five foot cube of dirt every 6 seconds. This means he can cast it 600 times an hour moving 3,000 cubic feet of soil. This seems a bit much, so i was trying to implement a mental fatigue if our wizard is trying to constantly use cantrips outside of combat, but was unsure how to balance it. 

Looking for some community feedback or experiences on how i should manage this.

I guess you could have him make a constitution save every  intelligence mod minutes of continuos use, and for each failed save he takes a level of exhaustion.

Casting spells can be taxing at a physical level, not only mental, IMHO.

As long as it doesn’t break the game, let your wizard use Mold Earth to do large scale excavation that way. He won’t use it that way for very long and that spell is primarily for use outside of combat anyway. 

If he moves too much dirt at once, the small village won’t be able to do anything with it anyway. By the time they’re able to build buildings, 3/4 or more of the basements that he digs out will have fallen in and they’ll ask him to come re-dig them. And any wizard will get frustrated being called to dig out basements 1 or 2 at a time. 

Personally, I'd Iet him use it as intended (maybe not more than 4-6 hours a day as it takes time to walk from one place to another, take a second to think about what to do next, coordinate with others, etc.). Then think about what that means for the story: who notices this sort of activity? What does it disturb in the ground? I love players willing to do stuff like this because it gives us lots of opportunity to do interesting things!

Hmm, perhaps i will allow it for say an hour at a time with a con save. But be very strict on how he moves/places the earth, or make him do dexterity rolls to see if the dirt pulled out causes surrounding earth to cave in.

Anyone else have any thoughts on this, i have a hard time when I'm playing sometimes as my wizard is very literal on the uses of spells and magic items. He does try to combine things in perhaps unintended ways that would potentially break the game. I don't like limiting his use of magic (spells and/or items) but sometimes it feels like i have to. if anyone has experience with this feel free to let me know any tips.

Considering there's spells with casting times of 1 and even 8 hours, spell slots already represent the physical and mental toll that spellcasting takes on the caster, and there's full time jobs that are much more physically-demanding than saying some words and waving your arms a bit, I wouldn't penalize them.

Just treat it like any other job that involves a lot of talking and moving around. If they have water to stay hydrated and keep their throat from drying up and don't skip lunch, they can have a productive workday. Mold Earth is basically designed for this kind of scenario, and it doesn't come up all that often. Let the wizard shine.

I would allow it. If they want to spend all day using their magic to move dirt around and it is doing a valuable service, I think it's a great RP opportunity to let them feel powerful in a non-combat situation.

I'd let it go. 5 cubic at a time isn't much before you need to do puzzle management.

Just remember that for something like Move Earth, the dirt is only moved 5-feet. This means that the caster needs to integrate his spell casting with those who are actually moving the dirty. What's I'd do is figure out what it would take a normal person to do (possibly a team) and maybe allow the caster to do the work of a small team of workers.

This is what I did back in 2nd & 3rd edition.

Yeah. I use it all of the time in combat to build a quick wall we can use for cover against archers. That takes 2-3 rounds. 

The spell does have limitations. You can only move the earth 5’ so that is the deepest hole or highest mound you can build without moving the earth through intermediate steps. It also assumes that the area only consists of loose earth. Sure that would be fine for farmland but most natural areas would have a percentage of rock. Also the spell doesn’t allow the caster to compact or shape the 5’ cube of loose earth, only move it. So if you wanted to build a rammed earth wall you would need to compact and shape it by some other means. The “move” feature of the spell simply allows a 5’ cube of earth to be moved a maximum of 5’ along the ground into a loose pile. It is not a “I build a bridge or wall in a few minutes” spell.

I see nothing game breaking about a wizard creating a 5’ mound in front of a 5’ ditch. But building a 20’ wall would be a slow and difficult process.

Yeah, the only thing I see that this should cost him in a game situation would be downtime, and maybe a level of exhaustion after so many hours of tedious work. I do like the idea of his excavation creating new problems to be solved. “Ok, so you’ve carved into the side of this hill to create a level road for the main street. In doing so, you’ve discovered this hill was not natural, but a buried-over building. [Party Cleric], given your knowledge of religious matters, you can tell this is a temple. Make me a religion roll to see if you can tell based on the symbolism which god it was built for.”

A great spell for construction, out of combat, is Wall of Stone.

It can create non-magical walls of stone that become permanent with 10 minutes of concentration. The fact that they are non-magical means they can't be dispelled. A fantasic spell for construction stone buildings and walls (with multiple castings of course.