Spelljammer How Easy Would it be to Convert Spelljammer to 5E?

[Zardnaar]

Assuming you used the 2E material where you can? For example the create helm spells being non combat related are probably fine.

5E has siege weapons in the DMG and while basic 5E also has stats for some vehicles so you could either convert so some sort of ship based combat rules would be useful assuming you on't just more or else recycle the 2E one. You can probably port in a lot of rules from 2E just subbing in 5E skills and tool/vehicle proficiency over 2E NWP system. One could probably borrow Star Wars Saga Edition ship rules and tweak it for 5E numbers.

Apart from that it seems mostly descriptive. Things like the sword coast could be transposed to any planet or even a suitably large asteroid and the ships could be more like taxis or flying dungeons the PCs can fight on. "Chult" is where Venus is or at least where the PCs make planetfall, Icewind Dale is a asteroid out near mars, continents etc can be small worlds. Spelljammer much like Eberron is one of those settings where anything goes.

If you just wanted to fly around in space and pirate via boarding missions it seems you could probably almost run SJ as is.

 

[QuietBrowser]

Honestly? I'd take a leaf out of Plane Shift Amonkhet's book: for the most part, we don't need complicated rules for spelljammer; it's just a cosmetic tweak for overland travel. I know that AD&D had dozens of new subsystems to handle speed, cargo haulage, etc, but the reality is that AD&D just tried too hard to simulate reality (a common problem for RPGs of the time), and frankly most of what you actually would do with a spelljammer can be handwaves. Borrow rules for siege weapons & structures to spice up the ship vs. ship boarding actions and frankly you're pretty much good to go in terms of basic mechanics.

Now, converting classic monsters or PC races, that's where you need to start putting in a lot more work...

 

[Enevhar Aldarion]

Mike Mearls has already done it and run games at conventions using his conversions. Considering how busy his official work schedule is, it can't be that hard to do. Also, I am not sure if he has put any of his conversions online or if any of his Spelljammer games were recorded and uploaded anywhere, but you might find something if you search for them.