First off, this community is fantastic, thanks again for all the help. If I were to go with an earlier edition module after Phandelver, how would I go about converting it? Any tips? I'm not familiar with the mechanics of earlier editions and still getting familiar with 5e. Are there conversion resources out there? Many thanks again to all!
The best resources are the 5e core books.
You can't go too wrong with just running old adventures as written (5 orcs over here, 1 ogre over there, etc.), just using the 5e monster stats. I have found this to result in much easier encounters, though. My advice is to do the math for encounter building (there's a spreadsheet for that somewhere around here). See what difficulty it gives you, ask yourself if that's the difficulty you want for that encounter, and adjust from there.
For monsters that aren't in 5e, it gets a little trickier. Whenever you can, base new monsters on existing monsters. A gibberling is basically a goblin. An aranaea is basically a giant spider.
Keep in mind that 5e monsters are a lot simpler than 3e-family monsters. If you see an NPC in RotRL that's like a half-orc fighter/barbarian with a million feats or whatever, you can probably just go ahead and use "orc" from the Monster Manual, and adjust the stats for the target Challenge rating. There's a page in the Dungeon Master's Guide that shows baseline stats for monsters of all levels. The players won't know the difference (or care). The MM also has basic NPC stats, and the DMG makes it easy to add monster races to them. If you really want to make it difficult for yourself, you can build NPCs using the Player's Handbook.
For everything other than monster stats, just make it up on the fly. Have the player roll whatever. They have to hit 10 to do something easy, 15 for something medium, or 20 for something hard. Done.
As for mechanics of earlier editions:
- Old-school editions (1970s-1990s) are mostly compatible with each other, and "d20" editions (D&D 3e, 3.5, and Pathfinder) are mostly compatible with each other. 4e and 5e are not directly compatible with each other, or anything else. They're both based on the d20 kernel, but 4e went in a totally different direction, and 5e is trying to have an old-school feel. If you see a D&D thing that looks like it was printed before Microsoft Word was invented, it's probably old-school.
- In most old-school editions, a "turn" means 10 minutes, and a "round" is 1 minute. Ever since 3e, a "minute" means 1 minute, and a "round" is about 6 seconds.
- Saves have different names; it shouldn't be too hard to figure out which one to use.
- Numbers (AC, hit points, etc.) do not directly correspond; you have to use 5e-specific values. Notably, in old-school rules, AC goes down (so a negative AC translates to a really high AC), and distance is measured in tabletop inches (which represent something different if you're indoors or outdoors; just ignore it if you value your sanity).
- Don't get too caught up with rules. Just try to figure out what the important things are, and try to represent that as simply as possible.
- Most published adventures suck, so don't be afraid to discard stuff and come up with something better.
