Advanced Dungeons and Dragons—”first edition” or “1e”—may be the most convoluted and confusing edition of the Dungeons and Dragons roleplaying game due to Gary Gygax’s penchant for verbosity and the Dungeon Master’s Guide (DMG) poor organization. Over the course of several posts, I will attempt to clarify those rules that tend to be the most confusing—especially those regarding combat.
The steps for encounters and combat are listed on page 61 of the DMG . Step one is: “1. Determine if either or both parties are SURPRISED.” Each side—players’ party vs. monsters—rolls 1d6. Normally, a side is surprised on a result of 1 or 2. However, if a member of a side has better odds, then those odds are used for the entire side. For example, a ranger is only surprised on a result of 1 on 1d6 (PHB page 24); therefore, the ranger’s party would only be surprised on a result of 1 instead of the normal 1 or 2.
If a side is surprised, the number of pips on the die is the number of segments of inactivity that side must endure. What happens if both side are surprised? Suppose side A rolls a 1, and side B rolls a 2. Sides A and B will be inactive for one segment (surprise cancels out for that segment), and then side B will be inactive for an additional segment, while side A gets to act. However….
If a side is surprised, individuals on that side apply their reaction adjustments (Dexterity Table on page 11 if PHB). A penalty adds lost segments for that individual, and a bonus negates lost segments for that individual. HOWEVER….
Dexterity reaction bonuses only apply if the individual falls under the “normal gear” encumbrance category; however, penalties apply regardless (PHB pages 101-102).