The Target 20 core mechanic provides an elegant way to resolve actions in classic D&D without the need for table lookups, complicated math, or recording of any new statistics. The idea is to simply check this:

For example, attacks can be adjudicated by taking fighting ability (fighter or monster HD) as "level", and Armor Class as the "modifier" (re: classic descending AC); e.g., fighter level 8 versus AC 4 rolls d20+8+4, and hits on a total of 20 or more. Similar usage can be made for saving throws, thief skills, spells known, etc.

A one-page PDF describing the details is to the left (click the picture). An Open Document (ODT) version is here. Statistical analysis of closeness to OD&D core numbers are given below (in XLS spreadsheets):

• Attack Rolls
• Saving Throws
• Thief Skills

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