I play a mad scientist Wizard. No one has no issues with me creating a army of golems...

I play a mad scientist Wizard. No one has no issues with me creating a army of golems, but the moment I want to make mechs, tanks, jets, and magic missile machine guns, everyone yells that I am crossing the line, both in game and in real life.

None of this isn't game breaking or overpowered. Is it?

Where would your character get the idea for mechs, tanks, etc ?

Mechs=giant golems
Tanks=giant insect shaped golems
Aircraft= winged golems.
Magic missile machineguns : Replace with self cranking, rapid fire, heavy crossbow or arbalest type weapons with a variety of enchanted/anti-magic/poisoned/alchemical rounds.
Problem solved, just refluff your creations to fit the setting.

>things that never happened

Get a competent non-shit GM who is not scared by change of status quo. Also, at that point you really should be starting magical industrial revolution.

>A setting where you have all modern military vehicles as various types of Golem.
I'd play this shit.

Two words: Spider Tank.

>Machine gun= golem that fires tiny golems
FTFY

Try to make it sound plausible. Eberron did the concept fine, you can't call it "mechs", call it stuff like "giant moving armor"

"wouldn't it be great if i could fire a bunch of arrows at a person very quickly" isn't an unreasonable starting point leading to at least something approaching a firearm
though if you're not roleplaying that and actually taking the time to go through the process, you're just cheesing "i want a gun lol" and that's gay

D&D magic can fundamentally change the nature of reality so it can probably handle controlled explosions launching mundane metals out of tubes at high speed.

I think the issue is less one of game-breaking or overpowered, and more one of setting and tone. The GM and other players want to play in a medieval fantasy world, which things like mechs, tanks, jets and machine guns tend to be at odds with. As others have suggested, just re-fluff your inventions to be more in keeping with the world. Mechs for the machine, advanced magic items for the personal tech.

or just a golem based firing device instead of a mechanical one, but still firing storms of metal darts

You're boring.

I'd also try to go more Dwemer-esque with the technology, so lots of mind-over-matter sorts of mechanical wonders that standardize and apply magical principle with stark efficiency.

You're silly. But I suppose given the resources destructive golem slugs would be pretty deadly and fun to use.

>None of this isn't game breaking or overpowered. Is it?
How could it be? None of it even happened.
I'm not even sure you're actually playing a game in real life if you don't have anything more plausible to tell us about yours.

We need to take this even further.
>Tiny Golem armor, Son. They project a shield spell in response to physical trauma.

I prefer my fantasy settings to have some truly spectacular scifi elements in small, scattered concentrations. Not enough to modernize civilization at large, but enough to keep things from being all farmers, wood, shit, and iron all the time.

>I prefer my fantasy settings to have some truly spectacular scifi elements in small, scattered concentrations
I had an idea for a Sci-fi setting that basically went the other way with it; The Post-singularity Super Intelligences running the Mega Corps have advanced to the point where they can bend reality on a whim and are effectively Gods, where as "Mortal" society has basically become a space-fairing rendition of classic sword and sorcery due to the influence and decisions of these god-machines.

For instance, due to dismantling the Military Industrial Complex, guns aren't particularly wide spread, thus "Rangers" are basically /k/ommandos who know how to make their own Firearms and Ammunition.

I like this.

Am I the only one noticing pic related?

I want a cute pet bullet golem who runs into things really hard like a baby ram testing out his horns

Its immersion breaking. Golems (presumably) already exist in your setting. You having the idea to build golems and obtaining the knowledge to do so isn't unreasonable.

For mechs, tanks, jets and machine guns? You want to invent 4 different things that were made by completely unrelated people over a period spanning between a hundred years and 'no one ever did', completely bypassing the decades of incremental inventions necessary to invent even a single one of those. The only reason your character has to even know what those things are is OOC knowledge.

So unless you are willing to craft 25 machine missile guns before you actually end up with a design that isn't shit, tossing all of that gold and xp into a hole for weeks, you're being an asshole who wants to skip to the good part without putting in the work for even the most basic of your 'inventions'.