A Surprising Look

Last updated: 210815

Surprise is elegant—one roll determines both whether one group is Surprised and for how many segments they are affected by Surprise. Dexterity (and other factors) can affect the number of segments a Surprised individual can be directly affected, but only adds or detracts to surprise segments only so far as that individual is concerned if the group was surprised.

A lot of the apparent complexity of Surprise arises from an assumption that a PC with a Surprise modifier (e.g., –3 Dexterity Reaction modifier) can act even though their party was surprised, when their individual Surprise segments are reduced to zero (or below). Yet while the rules explicitly state the surprising party acts, the surprised party’s ability to act is not mentioned (and even explicitly prohibited):

  • If surprise exists, the surprising party can use the time segments to flee/escape, close, or attack. PHB, p. 103.
  • [S]urprise also allows the surprising party to have that number of segments as shown on the die as the surprise factor as free and unanswered activity to move, attack, flee, etc. DMG, p. 49.
  • Each 1 of surprise equals 1 segment of time lost to the surprised party, and during the lost time the surprising party can freely act to escape or attack or whatever. If both parties are surprised, then the effect is negated or reduced [referred to as “Lost Segments” in the table]. PHB, p. 102-103.
  • A surprised party is caught unawares or unprepared. In such circumstances the non-surprised (or less surprised) party has an immediate advantage which is reflected in the granting of 1 or more segments of initiative, during which the active (non or less surprised) party can take actions 4. A. through H.,)… DMG, p. 61.
  • If surprise is indicated for both parties concerned, the party which has lesser surprise subtracts its result from the result of the greater to find the number of segments the [surprised] are inactive. DMG, p. 61.
  • [D]uring the surprise segment or segments, the surprised party is unable to react in any way. DMG, p. 61.
  • Party B is surprised (since they rolled a 2), and will be inactive for 2 segments. DMG, p. 71.
  • As party B is surprised for 2 segments, party A has a chance to hit in each segment as if they were full rounds … Aggro would normally get another chance to hit Balto, who would be inactive for another segment, but Balto’s dexterity allows him a +1 reaction adjustment, which means that he personally will be surprised for one less segment than the rest of his party. So this segment he is up and on his guard, and Aggro does not get another hit attempt this round. DMG, p. 71. [Balto doesn’t act due to his Dexterity Reaction modifier, just not be attacked].
  • The Dexterity reaction bonus allows the individual “to mitigate” [not remove] the surprised condition. DMG p, 62.
  • The Dexterity reaction bonus “adds to existing surprise [segments] or detracts from it [existing surprise]”. DMG, p. 62.

So what if PCs can’t act when their party is surprised, regardless of modifiers? When you don’t make the assumption that members of a Surprised group can act during Surprise, the exceptions that cause ambiguity are resolved.

Let’s demonstrate.

Process: Each party rolls Surprise. A normal party is surprised on a 1-2 in 6. On a 1, the party is surprised for 1 segment. On a 2 the party is surprised for 2 segments. On a 3-6 the party is not surprised. For creatures that are Surprised on a different range (e.g., surprise 5 in 6), results are calculated the same as those surprising 2 in 6 (except, of course, for more potential Surprise segments).


“If both parties are unsurprised, or equally surprised, determine INITIATIVE for that round.” DMG, p. 61. If both parties are surprised for the same number of segments, the net result is no Surprise—move on to Initiative. If both parties roll results in their range for Surprise, Surprise is calculated based on the net of the two results:

Assume A [surprised on 5 in 6] rolls a 4, so it is surprised for 4 segments unless B rolls a 1, in which case A party’s inactive period will be only 3 segments, or if B rolls a 2, in which case surprise will last for only 2 segments (4–1 = 3, 4–2 = 2). DMG, p. 62.

If one side rolled Surprise for 2 segments, and the other for 1 segment, the net result is that only one party is surprised—for 1 segment—with any Surprise modifiers calculated for individuals in that party:

  • Dexterity: +3 to –3 segments
  • Encumbrance: +1 to +2 segments

In other words, the number of Surprise segments for an individual can be modified –3 to +5. Which specific modifiers aren’t important for discussion, so no need to complicate things by referring to anything but the result, and examine the extremes (See https://dnd.sinister.net/im-surprised/ for a detailed analysis of Surprise modifiers).


Scenario A: Orcs and PCs both roll a 3. Regardless of applicable Surprise modifiers, there is no Surprise, and both sides roll Initiative.

Scenario B: Orcs rolls a 1, Party rolls a 1. Both parties are surprised for 1 segment with a net result neither party is surprised. No modifiers are calculated. Both sides roll Initiative. The same result if each side rolls a 2.

Scenario C: Orcs roll a 1, Party rolls a 2. While both results indicate Surprise, the net result is the party is surprised for 1 segment. Applicable modifiers are applied to any individuals in the surprised party, but not the (less-surprised) orcs.

We have three party members at the extremes:
Member 1: Inactive due to Surprise for 1 segment (default)
Member 2: Inactive due to Surprise for 5 segments
Member 3: Inactive due to Surprise for –3 segments

The orcs have one Surprise segment to perform an action. If casting a spell, the orcs can complete one segment of spell casting. If the spell takes longer than the 1 segment of Surprise, the remaining segment is completed during Initiative (a separate discussion!). Orcs can otherwise take a standard Surprise action. If an orc directly attacks Member 2 (already within 1″ for melee, or a ranged weapon), the orc could attack for 5 segments (don’t get heavily encumbered with a Dexterity of 3!). If directly attacking any party member with no remaining segments of Surprise (i.e., Member 3), the orc’s action is ineffective, and deferred to Initiative.

Spell Casting in Surprise

Another debate is how many spells can be cast during Surprise. Let’s look at the rules:

In such circumstances the non-surprised (or less surprised) party has an immediate advantage which is reflected in the granting of 1 or more segments of initiative, during which the active (non or less surprised) party can take actions 4. A. through H., wholly or partially depending on several modifying factors.

Most spells cannot be cast in a single segment, although first level magic-user/illusionist spells ore usually but 1 segment long, as are some other spells, and these spells ore possible to use in a surprise segment. Other, longer casting time spells can only be begun in the first segment of surprise.

As party B is surprised for 2 segments, party A has a chance to hit in each segment as if they were full rounds (this does not apply to spell use, of course). (DMG, p. 71)

There’s no prohibition of only one spell during Surprise. During each segment of Surprise, members of the Surprising party can take actions 4.A through H, which includes “cast spells”. If the spell caster has three segments of Surprise to act, they could complete three segments of a four-segment spell, cast three one-segment spells (one for each segment of Surprise), or move one segment, and then cast a two-segment spell. Spell casting is limited by time, unlike a normal combat round.


A Surprised party member, regardless of modifier, still does not act. They’re simply unaffected by direct actions from the other side once they have zero Surprise segments. [This is actually the critical sentence; it’s VERY tempting to say they get to act here, but the DMG says the Surprised party cannot act, and the Dexterity Reaction modifier detracts from Surprise segments, not that it permits acting during Surprise, nor does the DMG or PHB say that modifiers can make them unsurprised.]


Only after everything is resolved for Surprise do both sides roll Initiative, start a new round, and proceed from there.


Author: Rick

A DM for *mumble* years, I've been playing AD&D since junior high. I've currently got two separate campaigns running, both in Mystara. I've been told when they handed out hobbies, I stood in the short lines. I actively cycle tour, kayak, play board games, read, develop home automation software, play Stars!, volunteer with the International and National American Red Cross, and work on a never-ending stream of home repairs. In my wake I've left paintball, medieval full-contact combat (SCA), computer gaming, Heroclix, and kite construction.

4 thoughts on “A Surprising Look”

  1. OK. Two questions.

    1) If a member of the surprising party accidentally(?) attacks a PC that is not surprised due to dex adjustment—what happens? Does the orc pick on someone else or just lose the surprise attack?

    2) If a spell takes says 4 segements and is started in the surprise segement…which segments on the regular round does the spell complete? e.g. what is both parties roll a 5 for initiative. Does the spell go off before anyone gets to act?

    1. 1) The _key_ point here is that the Dex adjustment doesn’t “unsurprise” someone. They’re still surprised. They can’t do anything but (we’ll say just barely) prevent an attack on themselves at an individual level. If the orc attacks them the attack gets deferred to Init (which, yes, means he loses the Surprise attack).

      2) Once you get into spells, standard AD&D, segments, and Initiative you get beyond my scope. Because while I (with some Surprise on my part) think I’ve untangled Surprise, I don’t see any hope for doing so with 1e Initiative. So the only thing I can say is one segment earlier than it would have gone off otherwise.

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