Almost any material you come across for 0e or other early editions of the world’s most popular roleplaying game can be used in Dungeon Delving Undying Light with little modification. However, some descriptive conventions that early editions used may need some explanation.

Time Conventions: Early editions talk about time in terms of rounds (combat rounds) and turns. In 0e,a round was 1 minute and a turn was 10 minutes (as it is in this game). In B/X, a round was 10 seconds and a turn was 10 minutes, so there were 60 rounds in a turn.

Movement/Distance Conventions: Early editions gave distances in inches. When underground or in buildings or the like, one inch equaled 10 feet. When outdoors, however, one inch was 10 yards.

Adventure Conversion Guidelines: There are a large number of published adventures designed for early editions of the world’s most popular tabletop fantasy roleplaying game. These adventures can be used with Dungeon Delving Undying Light with only a little conversion. The following guidelines will make conversion easy.

Armor Class (AC) remains unchanged. Exception: First and second edition adventures start their armor class at 10 instead of 9. Consider an AC of 10 in such adventures to be an AC of 9 [10].

Dungeon Delving Undying Light defaults to a d6 for HD and basic weapon damage whereas adventures default to a d8. Therefore, do the following:

HD/Hit Points: Decrease the hit points of published monsters by 1 hp per HD. If hit points is not listed just roll the Hit Dice using D6s.

Damage Rolls: Convert the dice used in published adventures to the d6 standard using the following table:

Adventure Die D6 Standard
1d12 1d6+2
1d10 1d6+1
1d8 1d6
1d6 1d6-1*
1d4 1d3
1d3 1d2

* Minimum of 1