Specifically, grape farming. You can pay off the debt in a few days without ever going into a dungeon by selling the initial objects you start with and starting a grape farm. Each grape farm, when worked, produces many thousands of grapes per day, which then sell for 2 zorkmids per grape to the alchemy shop. 

You could divide the number of grapes you get per day by 10 and it'd still outpace the rate at which other types of passive income generate value by like double. 

By just starting a grape farm, I was able to pay off the debt in 9 days over 23 irl minutes. I'm sure a speedrun could get it much faster. 

Other types of farming are probably also too profitable - you make more money farming a greenhouse and then selling the resulting vegetables made by 1 laborer than you do having 5 miners mine, selling all the stuff they get you and then pressing the gold they get into fake coins, and also more than you would having 4 mages harvest crystals every day, despite both of those requiring way more setup and requiring paying many more people. 

Oh wow, a single vineyard producing thousands of grapes per day is definitely a bug. They should produce at most 2 grapes per trellis, which I think would be 80 on a max-size vineyard, which is probably still too much but also not a automatically-win-the-game amount.

I’ve tracked down what’s causing it and it’ll be fixed in the next release, which should be out on the 1st. I’ll probably be extending the time it takes to grow plants too. Thanks for playing and for reporting it!

Thanks for looking at my post! While we're on the topic of bug reports, I encountered repeated (kind of save corrupting) crashes that I think might have to do with going on missions to noble mansions while having debt collectors after you (though i'm not entirely sure). Where would I go to report things like that? 

Here is fine. If you have an error code that’s occurred, please post it, and if you have one of the corrupted saves, you can send it to contact@weirdfellows.com

Saves can be found: ~/.local/share/wizardschooldropout/saves on Linux C:\Users(YourUserName)\AppData\Roaming\wizardschooldropout\saves\ on Windows

I'm on linux. I'll see if I can reproduce the issue and then email the saves. There's no error code, just a black screen upon entering a mission in some circumstances which persists even if you load a save, and during which the game is unresponsive. I've only been able to avoid it by keeping backups and trying to pass time / go into other missions before re-attempting the seemingly bugged one. Loading the bugged save tends to result in the auto generated backup being replaced with one in the bugged black-screened mission and borking my playthroughs. 

I noticed the issue when attempting to enter Noble house missions while deep in debt and with many debt collectors after me, even very early into the game. Once I paid off the debt the issue stopped occuring, I don't think I noticed it happen a single time after that, which makes me think it may be related. If it matters, I was only going on missions to noble houses (not sure if it happens in other areas) and whenever possible, would kidnap two people to harvest them for blood, set up the blood harvesting, then go on another noble house mission. Doing this from a new save caused the issue repeatedly even if I quit and restarted the game and made a new playthrough.

I've also had issues with the acid splash spell which I think just doesn't work at all. Most of the time that I cast it it just doesn't do damage to enemies, or does at most 1 even though I had the damage upgraded to 13, and then when enemies walk on the acid instead of taking damage the game throws up an error code.  And I think non-human wizards are unable to be assigned to jobs like crystal gathering or research which human wizards can do for some reason, which makes them less worth hiring.