So, you wanna play Classic Doom?

Well you read the title, not much else to it. This is my best attempt at a "Getting Started" guide for playing Doom wads, covering everything from the very start up to a few starter wad suggestions to get you going. This is by no means a definitive guide, and you're free to do whatever you want, but I figured it'd be nice to at least provide my personal take on this stuff.

STEP 1- ACQUIRE DOOM
Very simple, and there's a few ways to do it. Getting Doom 1+2 on Steam is the easiest, but unfortunately that costs money, and if you're picky those versions of the IWADs also have the health packs recolored to green instead of red. With some digging you can find the original IWADs floating around all sorts of places on the internet if you want, but unfortunately I can't link these here because that's illegal. Lastly, there's Freedoom, which is completely free to download legally, but has all the sprites redrawn to look completely original. There's a version for both Doom 1 (Phase 1) and Doom 2 (Phase 2), with the Doom 2 version also containing texture replacements for the new textures exclusive to TNT and Plutonia. Unfortunately some stuff doesn't look quite right when using Freedoom since most wads assume all the assets will look just like they normally would, but functionally there's no issues.

STEP 2- CHOOSE A SOURCEPORT
This step is a bit trickier, since there's a LOT of different options and much of this comes down to preference. I'll give a quick rundown of the highlights and let you make your own choice, but once you get deeper into things it might be a good idea to go looking around in more detail.
UZDoom - This is probably your best first choice. It's filled with modern features and is very customizable, and is compatible with basically everything aside from a handful of wads that require VERY specific functionality. UZDoom does run into some performance issues on larger maps or maps with a ton of enemies, and a few things work slightly differently under the hood, but unless you're a speedrunner or in need of very specific compatibility then UZDoom is all you'll ever need. There are also a good number of wads that rely on UZDoom exclusive features to work so it's good to at least have it on hand to play any of those.
DSDA-Doom - THE speedrunner sourceport. It's stricter when it comes to compatibility and less customizable, but it performs better with larger maps and supports recording demo files, at the cost of feeling a lot less modern. I personally don't prefer it but enough people swear by it that I figured it deserved a mention here. Additional note: Switch from Software to OpenGL mode in the video options and you'll get fully unrestricted mouselook without the weird stretching effect! There's also Nyan Doom, a direct fork of DSDA that has a bit more customizability in terms of options (like my favorite: being able to turn off infinite height enemies), and has become my preferred sourceport after exclusively using UZDoom for several years.
Nugget Doom - Very similar to DSDA in a lot of ways, though less speedrunner oriented. It's compatible with anything that relies on Boom or MBF21 features, and is decently customizable (though not as much as UZDoom). Essentially the inbetween of UZDoom and DSDA.
Doom 1 + 2 - Also referred to as the KEX Engine, this is the sourceport that the recent Steam re-release uses. It's mostly compatible with the same stuff as Nugget Doom, although some wads with extensive Boom or MBF21 usage break a little and may require a specially made version just to work with this port, and it's one of a handful of ports to support ID24 features. Getting custom wads to work with this port can be a bit finicky, and the built in mod browser is full of unofficial reuploads, but it's a fine enough way to play most stuff.
Chocolate Doom - The closest you're gonna get to experiencing Doom just like how it released in the 90s. It's INCREDIBLY limited in customizability and pretty much only works for vanilla compatible wads, but it's here if you really want it.

STEP 3 - FINDING WADS
Alright, you've got Doom and you've got a sourceport, now it's time to play some wads. With over 30 years worth of content there's not a clear place to start, and there isn't really an officially agreed on starting point but I'll do my best. Note that this is NOT a list of the best wads, just a few wads I think make for a good introduction to Doom as a whole before you go off and pick out whatever else you wanna play on your own terms. Before the actual wad suggestions I do have a disclaimer to make: Don't play everything on Ultra-Violence difficulty unless you know that's what you want. UV is designed as Doom's "Hard" difficulty, despite a lot of people swearing by it as the "real" way to experience Doom, and might not be the most fun for a blind first playthrough. If you wanna throw yourself into UV on every wad from the start go right ahead, but just keep that in mind.

The IWADs - Simple answer but if you've never played Doom before, might as well start at the beginning. This is a good way to get familiar with all the weapons and enemies, and they're easy enough that this isn't a bad place to get started. If you do choose to go down this route first you're best off just playing through Doom 1 and 2, and skipping out on TNT and Plutonia for now, but you should consider playing through those eventually sometime down the line. Unfortunately starting with the IWADs does have a pretty major caveat: these games are over 30 years old, and 90s era id Software wasn't the greatest at level design. Expect a lot of unclear progression, very ugly looking areas, and some very questionable layouts.
Nostalgia by myolden - This is my personal pick for where to get started if you wanna skip out on playing the IWADs. Nostalgia takes Doom 2's original structure and set of episodes (Techbase, City, and Hell), and gives it a modernized coat of paint for both level design and combat. Nostalgia is about on par with the IWADs difficulty-wise, and is MUCH better.
Overboard by mouldy - This will always be my go to "Hey, look at how cool Doom can be" wad. It's short, punchy, full of heart and soul, and even has a bit extra to chew on if you want a little more and thought it was a bit too easy.
Portraits of Doom by Peccatum Mihzamiz - This was my first proper classic wad, and so it kinda cheats its way to getting a mention on this list, but it does an alright job introducing you to everything, and has a fun New Game + feature that has you replay the entire thing with remixed enemy placements that now include everything from Doom 2, with the environments changed to reflect that you've already been through here once before.
The Lost Magic / The Quinary Conundrum by Vortale - These aren't as traditional as the prior wads, with a few custom gameplay changes in TQC and plenty of reskins in both, but these two wads are an instant hit of fun, with a focus on shorter maps that take you through a variety of unique visual themes. TQC especially is a REALLY fun ride, and I'd recommend it even if you're deep into custom WADs already.
DBP37: AUGER;ZENITH / DBP59: Zeppelin Armada by Doomer Boards Community - Technically any of the DBPs would be a solid start, but I find these two to be the highest quality ones while also not having any especially insane difficulty spikes. The Doomer Boards Projects are all about visual variety, and while the specific mappers involved changes depending on the project, on average they're calibrated on the easier side of things which makes for good early wads to try out.
TNT: Revilution by Jaws in Space et al. - This one's a bit harder than my previous recommendations, but it's a great showcase of the average community project experience, wrapped in some great TNT: Evilution flavoring

STEP 4 - GET A LAUNCHER
Alright, you've got everything you need, now let's make actually launching this stuff a little easier. There's several other options out there, but I personally HIGHLY recommend using Doom Launcher. Just drag and drop your WADs onto it and tell it where all your sourceports are, and then you can just run everything from there once it's all set up. Doom Launcher also lets you create tags to better organize your stuff, have multiple profiles for every WAD if you've got multiple settings templates you want to flip between, and you can even browse the idgames archive within it! Getting used to Doom Launcher might take a bit but it's an incredibly valuable tool if you're planning on having a large collection of WADs and want a great way to keep everything organized.

STEP 5 - HAVE FUN!
Doom is great! And what's great about it is how much freedom you've got for how you personally want to experience it. There's tons of wads that cover all sorts of themes and styles, a lot of sourceports to suit whatever your needs are, and several difficulty settings to control the experience. The only thing that's the same for everyone is your 3 basic goals: Get guns, get keys, kill demons. Now get out there and start shooting!