Monday, May 9, 2016

Surprise! It's..a flowchart.

CharlesDM's surprise tree here at this link is reproduced in convenient flowchart form below:

I'd appreciate chances to fix, clarify and/or improve, still somewhat a work in progress.

Green is Yes/Success to a question or roll, red is No/Failure.

Note I differ from Charles' presentation in that I assume if you are a thief you would still want to Move Silently against an inattentive target so that you can deny them their Hear Noise - every little bit helps.

The difference in not doing so, perhaps, is movement speed - do you want to take your chance and get up to them right now, or take a slightly different chance and get to them in another round?

Whether or not concealment is available should be irrelevant to an inattentive target - a Judge could allow the thief to be quite nervous about making her throws while knowing that failure doesn't matter.

Operationally, then, what does this tell us?

If no concealment is available, the attentive target gets their regular surprise chance. This is modified by character classes or proficiencies that give a player the ability to impose a penalty on opponent's surprise rolls - barbarians, for example, being Naturally Stealthy.

Note that when we ask if "concealment is available", this is referring to the last critical point in the approach - you may have been hiding behind 300 foot of warehouse wall for the last X number of rounds, but this is at the critical point of coming into contact with your target with intent. (or, alternatively, if an unknown observer is present that could notice the thief)

If concealment is available, for the attentive target, these motions get us to the point where we can attack/interact within one action/round. Again, the naturally stealthy folks get a general bonus, whereas a thief can take the extra options of the two sneaky skills to completely deny the target their surprise rolls.

Any thief should take the opportunity to gain that proficiency if the Judge allows. The math is ever in their favor.

If the target is inattentive, then it's a easier task. The thief may invoke a Move Silently roll to deny the target a hear noise to notice them coming. Everyone else either hopes the Hear Noise fails, or relies on regular surprise.

Interestingly enough, while there's a proficiency/power that allows one to impose a surprise penalty to opponents, there isn't one for Hear Noise - there's no opposing proficiency to Alertness in part or in full. Hear Noise at it's default 18+ is so bad as to not really deserve further penalty.

I've talked about that a bit here in regards to collapsing "sneaking" into a single roll.

Inhibiting Hear Noise is purely the domain of the Move Silently skill, and Hide In Shadows is the only opposing mundane force to an attentive target, if concealment is available.

Also, imposing a -1 surprise penalty is worth more (1 power) than a +1 bonus to one's own roll (usually a secondary benefit to a +1 initiative) (ACKS PC, pg 98). That's the value of surprise, offensively.

A secondary note; Inaudibility (ACKS PC pg 137) can be recast as a very minor (4.41 points, I think) 1st level spell that lasts 1 round/level. If one treats the thief as permanently a 1st level caster, Move Silently is essentially casting that spell with a successful throw.


  1. I think part of my confusion with all of the surprise rules is how a Judge determines the party of PCs saw a group of monsters before that group saw the PCs. If there's a group of gnolls hanging out at the entrance of the Caverns of Thracia at dusk the Judge just sort of determines by fiat that one or more PCs saw that group from a distance and none of the gnolls saw the PCs and now the PCs have an opportunity to sneak up on them?

    In such a case, this chart seems to indicate that the party cannot sneak up on attentive gnolls even if there are lots of trees and ruins around (concealment) if they are not thieves with anything other than the surprise roll, is that right?

    Is the default of fantasy dungeon delving games such that adventurers are always assumed to be attentive unless the PCs are arguing among themselves, and that monsters default to inattentive even if they are assigned a guard post, and that they only switch to attentive for short periods of time if something pretty major has occurred to warrant it?

    If monsters are surprised and PCs are not, it might still be the case that the PCs can simply watch and the monsters remain unaware, is that right? Just sort of depends on the circumstance and whether there are things to hide behind? If that's right, maybe there's yet another sub-routine in here that needs expression:

    Concealment is available and the party as a whole are not thieves and the monsters are surprised = monsters unaware and the PCs can decide to watch and then perhaps move away undetected (leading to some other determination method or maybe the Judge just always allows them to sneak away from surprised monsters)

    Concealment is not available and the party as a whole are not thieves and the monsters are surprised = a surprise round for the PCs but the monsters are aware of the PCs and it is on (depending on a subsequent reaction roll, but the context is armed strangers who appear to be sneaking up on the monsters).

    I have other general questions but that's good to start.

  2. Who sees who first is essentially the surprise roll - if the gnolls are attentive, and the party either has no thieves or the thieves they had weren't sneaking, then regular surprise is rolled.

    Surprise is the reaction to the change in state of someone appearing, however far away they appeared - that's their chance to internalize the situation and be ready to act.

    How far away that distance is can be determined by an encounter distance roll (pg 96/97) or by whatever resources the Judge has available - a map of the area, etc.

    And you are correct - non-thieves cannot sneak up with concealment with anything more than surprise. The thief skills are specifically for denying opponents their Hear Noise or Surprise rolls.

    There's basically 3 states of readiness: Attentive, Inattentive, Distracted.

    I don't believe adventurers are meant to be always attentive, and their attention on watch fades just like monsters. They can also be distracted. Events can happen to upgrade through the states - the captain walks by, and the guards go from Distracted (they were betting on dice, and they Heard Noise and made their Surprise roll versus him, at least) to Attentive for a turn, let's say.

    It may be there should be another tree for Distracted.

    Consider the following three situations:

    A PC emerges from concealment -distance doesn't matter: he is within the field of vision of the monster.

    If the monster is Attentive, the PC is seen and the monster is not surprised (does not roll) and it's aware of the PC - it'll act on initiative if required.

    If the monster is Inattentive, the monster rolls Surprise. If the monster is surprised, it did not detect the PC (for any reason, it checked it's watch, scratched an itch, whatever, doesn't matter). The PC has a single round to do whatever. If the PC is still in sight the next round (having not engaged the monster), another Surprise roll is done. (This is the bit in TV shows where the hero sneaks by an open hallway and the guard at the far end doesn't see him or her)

    If a monster is Distracted, concealment is not necessary, which is somewhat implied but not really detailed in that chart. The monster requires a successful Hear Noise roll to upgrade to Inattentive (the thief can deny the monster this chance by Moving Silently). Then, the monster requires a Surprise roll to notice the PC.

    It's probably important to note that Hide In Shadows is poorly named. The Chameleon spell from the Player's Companion doesn't make shadows, it makes camouflage, and gives anyone a 12+ (level 6 thief) to Hide In Shadows. Or, something like a ghillie suit, perhaps, could certainly give a bonus to Hide In Shadows - the skill is in knowing how to use the cover you have or can bring with you, not necessarily needing literal shadows to magically blend into.

    The Explorer's Difficult to Spot ability gives them a 3+ roll to disappear into existing underbrush, which is the same chance as a level 12 thief has to Hide In Shadows. The Explorer can't Move Silently, so he'd rely on people to come to him to surprise them in that situation, or he'd rely on Surprise rolls to get it done.