I am late to the party when it comes to 5th Edition
Dungeons & Dragons. The advent of 4th Edition pushed me into playing
Pathfinder, which I quite enjoyed. Although I helped playtest
D&D 5E, I did not feel any need to stop playing
Pathfinder. Then there came a 2nd Edition of that game, and I did not want to buy a bunch of new books. The birth of my son also meant that I did not have a lot of time for playing these games anyway. Also, there was a pandemic.
That was when three different events coincided to change the situation. First, my buddy-in-law Brent sent me a 5E Player's Handbook so that we could play some games in Google Meet or Zoom. Second, the guys for whom I'd run my last campaign decided to start a new one, playing 5E online. Finally, Wizards of the Coast announced that they would publish new Spelljammer material, and I was all in. I ran Light of Xaryxis as my campaign for the 2022-23 school year, and have been thinking about the subject since then.
All the while I was reading the 5E books, and quickly realized that the Monster Manual provided great stat blocks for monsters, with many of them having variations for different challenge ratings. What is more, many of them feature a leader-type and a magic-user, characters who nicely fill the roles of captain and spelljammer on ships. With that in mind, here's a table with which the DM can randomly generate Spelljammer encounters.
-Nate