Surprise is one of the bits of system that didn’t hold up under scrutiny and is worthy of a post on its own, I think. There’s a whole lot of tinkering going on with how surprise operates, beginning with how it feels and including what purpose it serves in the system.

Let’s begin with a look at how it plays out in RAW. I’ve long wondered why groups get surprised one-third of the time upon encountering another group or monster. Reading through all of the OG materials has offered no reasoning to support that rate, so this appears to be one of the things that has been perpetuated simply because of tradition. I decided that I’m not down with that; one-third of the time is simply more than I can sustain disbelief for–it just doesn’t serve my fantasy to have competent adventurers getting flummoxed by running into beasties that often.

To that end, I’ve moved to lesser chances, closer to 25% of the time. If I recall correctly, the odds are about 27%, using the dice roll I’ve landed on. I’m using the 2D6 roll that I’ve pressed into service for some other purposes.

I’m also all for PCs being able to bump the odds in their favor, whether decreasing the chance of being surprised or increasing the chance of surprising others. How the players play should matter and this is but another way their choices matter mechanically and fictionally.

How long surprise lasts has also not survived its viewing under the microscope. The initial measure being provided by the die roll, with a surprise result of 1 or 2 resulting in a matching number of suprise segments was an elegant way to find out long surprise would last. Two segments of surprise are also referred to as “full surprise,” which illustrates that two segments was the longest surprise would last, originally. Then, with the accretion of further rules, notions such as creatures that could surprise more frequently changed how many segments could be notched in that fashion. Tossing in the use of dice of a larger size — D8 or D10 — for surprise checks in some situations, and figuring out how long surprise lasts becomes muddled.

As I don’t think more than three segments of surprise is reasonable — especially with a one minute round — I’ve capped surprise at that. The number of phases of surprise is also established by the dice roll for surprise.

What surprising combatants are able to do during each segment of surprise also got limited. The notion that each segment of surprise garnering a full series of attacks, without regard to the number of attacks entailed, got dropped, too. Two attacks are certainly possible, depending on circumstance; anything beyond that stretched my sensibilities past breaking. And certainly no launching multiple arrows each segment, so only one readied arrow per phase, with a phase required to ready one. I’m also considering an added bonus to having surprised the opponents when the first full round of action fires up, which returns a bit of the overwhelming advantage provided by surprise in the RAW.

This has also resulted in dropping references to segments in the surprise rules, in favor of referring to phases. This is with the understanding that I’m also dropping the use of the term “segment” entirely, at this point, because of its long association with being one-tenth of a round; rounds will be apportioned in fewer parts when the whole is reassembled (five phases per 20-second round).

The urge to allow for PC actions (player choices) to affect the odds of surprise also extends to how long surprise lasts, measured by how much activity the surprising party can do before the surprised can engage fully and player choices can quicken response when PCs are surprised. As above, the number of melee and missile attacks possible will be limited, what movement is allowed carefully meted out, and what casting or other magical work can get started and/or finished. A surprise situation, under this approach, may not happen as often, yet it provides a major advantage to one side when it does happen.

Ambush

An ambush provides a different experience of surprise. Only the party being ambushed can be surprised due to the ambushing party knowing full well when it will act. How the ambush is set up and executed will affect how much activity the ambushing side will get to do before the victims can respond. A well-planned and -executed ambush can provide a bit more time for salvos, too.

Sneak Attacks

A sneak attack is a form of ambush, just on a smaller scale, so to speak. Sneaking up behind a guard to take them out or firing a crossbow from the darkness into a sentry’s back rely on the at-least-momentary lack of awareness and engagement, as much as springing forth from hidden positions along a road when attacking a caravan does.

A Rough Draft of Surprise Rules

Surprise: Roll For doom

https://osrpgtalk.net/wp-content/uploads/2025/11/DA-Surprise-v-0.8.pdf