Or if the character doesn't have 15 in two abilities allow them to slowly increase until this is met. You'd also have to account for certain racial maximums as well. 18 is obviously the maximum with Fighters getting +10 or +15 to their Exceptional Strength. Or you let one or two scores improve by X amount every Y levels. Leaving the rules as they are means xp is the preferred improvement reflected in the attack rolls and saving throws. I don't remember if this was ever brought up in all the argy-bargy and it seems important. You will find a passage on p9 of the 1e PHB where Gygax says your character is exceptional and thus should have a score of 15 in at least two abilities. Either your character was improving with experience and didn't need any tweaking of abilities or, since a Fighter was swinging heavy weapons and opening stuck doors, then the STR should improve.
The arguments revolved around xp versus ability score improvements. There were a number of articles and letters in Dragon magazine in those days which tackled the issue of improving ability scores - with varying degrees of persuasiveness.
By "long enough" I mean your character had hit their 50s or 60s.
AD&D 1E DMG UPDATE
Update 2 (April 28, 2015): Added 4th Edition Essentials books.Update 1 (April 25, 2015): Added OD&D Men & Magic 1st – 3rd Printing cover (based on note from Shawn Sanford in comments) Added Video slideshow version via YouTube embed (at bottom of post).Without further ado, the Dungeons & Dragons rulebook cover art throughout the years: Many sites were helpful in helping me remember (or learn about!) the various rulebooks and their chronology, but the three I found myself on most often were the Tome of Treasures, Wikipedia and D&D Classics. A nice shout-out to the 1e DMG this chapter catalogs how spells act. Scribd is the worlds largest social reading and publishing site.
AD&D 1E DMG PDF
I also hope for this to be an ongoing, fluid post as more information comes to light and (hopefully) folks point out things I’ve missed or books I should have covered but didn’t, etc. AD&D 1st Edition - Dungeon Masters Guide (Original Cover).pdf - Free ebook download as PDF File (.pdf), Text File (.txt) or read book online for free. So I hope you find this useful and fun to browse. I spent some time searching for a page like this that had everything all in one place for D&D cover art and couldn’t find it (although there are great resources out there, nothing seems to have it all on one page). What this is: a scrollable, one page list of D&D cover art for core rulebooks(or “semi-core rulebooks”, semi-core of course being subjective) rulebooks of the various versions of the Dungeons & Dragons tabletop RPG game.