If you’d like to understand why I made the thing, keep reading.
While this edition is better organized than the earlier games, it’s still a mess. Sometimes rules get tables, sometimes rules are buried in paragraphs, and some rules were forgotten completely, only to surface years later in an accessory book, or else are spread over multiple chapters and never reference one another.
Learning this system can be exhausting, as you can never be sure what you missed or if you’re even playing correctly. That’s not unique to this edition, even 5e has its moments of ‘oh look at this rule they tucked away,’ but in 2e it’s ever present. I was learning the system in order to teach it to a group of players whose experience with D&D goes back no further than 3.5, and I knew I would be their only lifeline to understanding its mercurial nature.
I searched the internet for a good quick guide, an overview, a cheat sheet, anything that could give me a roadmap, but there really wasn’t much out there. So I did what I usually do when learning any overly complicated and occasionally contradictory collection of information: I took notes.
Those notes eventually coalesced into a guide, and within a couple months of writing and play, I had something I found useful. I thought others might, too. I downloaded Scribus, edited the thing into something readable, and now it’s The 2e Primer.If you see errors or places where improvement can be made, please share them. I’d like for this document to be the tool I couldn’t find when I was searching for help; anything you can offer toward that end would be appreciated.
Nice doc - however you can simplify THAC0 even more. Roll a d20, add everything to it (bonuses, penalties, AC). If the number is >= THAC0 you hit. No need to modify the THAC0 at all. Easy Peasy.
ReplyDeleteLearning this system has been a lesson in how everyone appears to have handled THAC0, and attack rolls generally, in the way that made the most sense to them. Thanks for putting in your two cents!
DeleteI went with THAC0 - (Attack roll -/+ modifiers) < AC, because it made the most sense to use when hiding AC from the players. I agree that it's more work than needed if the players know the monster's AC or if you're willing to do some of the math for them. I go into this in a later post, if you're interested: https://nonweaponproficiency.blogspot.com/2025/09/to-hit-descending-ac.html