1st Edition AD&D Surprise: Not So Difficult

While learning AD&D at the tender age of 13, we made a lot of bad assumptions about the game and how the dice worked. Probability was new at the time and the elegance that Gygax used in creating a fast-paced and exciting game sometimes went over our heads. Surprise was one of those things. In retrospect, the concepts are not that hard to understand, just not explained as elegantly as the mechanic itself.

The Dungeon Master's Guide I feel makes a number of assumptions: 1) you've played wargames in the past; 2) specifically you've played original D&D with the Chainmail rules; 3) you've used the alternate rules in the Greyhawk Supplement before; and 4) you understand the convention of dice and probability as relates to most situations. Having never played miniature battles in my life, the conventions explained in the AD&D DMG were mysterious at times and assumptions made matter-of-factly made little or no sense to me. To make matters worse, the editing errors added another bit of confusion into the mix (the surprise segment table in the PHB or DMG is in error on one of the lines). My first gaming experience using surprise was non-standard at best (vs. drow in the underdark) so it's no wonder we got it all wrong.

The most important decision about surprise is if it exists. Obviously the chance for surprise is going to almost universally apply to the player characters since they are the invaders into the realm of the unknown. Creatures in the dungeon will almost never require light sources, are aware of the noises usual to their environment, and some can even sense intruders mentally or through special abilities. Magical wards being tripped , traps being set off, doors being broken down, etc. all lead to 0% chance for surprise for the monsters. On the off chance that the characters are able to mask their presence somehow (invisibility, all using infravision to see, demi-humans or thieves sneaking about, etc.), then the monsters MAY be surprised. Planned ambushes are another problem, however. A wandering monster is typically the only instance of surprise  most commonly occurring in a play session. So step 1 is determining who is aware and who can be surprised. As stated, surprise is usually unilateral and almost always against the players.

Step 2 is rolling to see if surprise occurs. In essence, the elegance of the roll is that 1d6 is used for both the chance to be surprised AND the number of segments of surprise. It's my belief that this is only stated for STANDARD 2 in 6 surprise; non-standard surprise where the surprise is given as a percentage or on a different die type needs to be handled by the DM. It is my belief that there should never be more than 2 segments of surprise [EDITED], as supported by the existence of "complete surprise" (see later article on surprise segments). In any case, only roll for the party that can be surprised, modifying the roll based on whether the monsters or players have a better or worse chance of surprising. For example, a ranger is only surprise 1 in 6. A bugbear can surprise 3 in 6. Assuming that only the ranger can be surprised, the bugbear has 1 in 6 chance better than normal so the ranger is surprised 2 in 6.

Step 3 is determining how long surprise lasts. If normal 2 in 6 chance for surprise exists, simply use the die roll to determine the number of segments. If a 1 is rolled, the surprise lasts 1 segment. If a 2 is rolled the surprise lasts for 2 segments. During a surprise segment, a character or monster is allowed its normal number of attacks, missile fire at 3x rate (not used by this DM), and can cast fast spells requiring 1 or 2 segments as required. Activation of magic items requiring 1 or 2 segments may also be used. The side that is surprised cannot perform any actions so long as they are surprised. Dexterity reaction adjustments reduce or increase surprise for the individual only. If a person has a +1 reaction adj. and his party is surprised for 1 segment, then he is not surprised and rolls for initiative as usual. A person with a -1 reaction adj. would be surprised for 2 segments; note that a penalty can never create surprise, it only modifies existing surprise.

Now, the controversy has to do with the terms surprise and complete surprise. These terms were used in the DMG with no explanation given. It has always meant to me that surprise is 1 segment and complete surprise was 2 segments. But nothing in the books supported this definition....until I re-read module G3. In the adventure there are some wererats on the 2nd level that are stated as always attacking with surprise (6 in 6), then gives a range of segments based on a die roll (1-3 = surprise, 4-6 = complete surprise). Now, according to the examples given, normally that would indicate 6 segments of surprise since 100% surprise is the same as reading 6 on a d6. However, there are a lot of creatures in the G-D-Q series with better than normal chances of surprise and a reduced chance of being surprised. How many segments should they get? The answer is to use the convention written into G3. Assuming the roll of an additional d6 with each surprise check, one die would represent the chance for surprise, and the second would indicate the number of segments of surprise (1 or 2). This could apply to ALL surprise checks, including monks percentile chance and odd monsters with increased or decreased chances of surprise. It all makes sense.

For another example, refer to the module T1, a very low level module that is meant as an introduction to AD&D. Most of the monsters in the moathouse have an increased chance of surprise and almost no chance of being surprised. In particular, the spider in the tower has a 5 in 6 chance of surprise. Should that mean that the spider gets 5 attacks on a hapless victim if the party rolls a 5? I think not. No more than 1 or 2 segments of surprise should exist, modified by Dexterity for the individual. After all, a spider attacking a 1st level character would have a good chance of killing them in the 1st encounter - not a good way to introduce AD&D to a neophyte!

So, the concepts are not that difficult to understand once you know where it all comes from. Better examples and clarified steps would have helped immensely. I'm so glad that I now have a handle on this concept and feel confident to house rule it when necessary.