Sneaking is a good Halloween subject, as it is the season to do so, in good fun.
There was a pile of discussion earlier on Autarch's boards about thief skills and the utility thereof. Lots of good ideas in there. One thing that came out of that was the proper methods by which one sneaks - a thief applies Hide in Shadows & Move Silently when applicable, and the targets get Hide Noise and Surprise rolls, when needed.
The process was expounded upon, resulting in a few 'choice trees' - CharlesDM of the excellent By This Axe I rule blog has one here, in fact.
Since we're dealing with dice, we're dealing with percentages which means we can simplify this down to scorched earth.
And I do so, on the table below. Note I've added another choice to the tree - the choice to Move Silently towards an inattentive target, so as to deny them a Hear Noise roll.
We'll proceed assuming my second time through Statistics stuck. ;)
| Attentive Target |
Inattentive Target
| |||||||
| Concealment |
No Concealment
| |||||||
| Hide Successful |
Hide Failure
| |||||||
Move Silently Successful
| Move Silently Failure |
Move Silently Successful
| Move Silently Failure | |||||
Hear Noise Failure
| Hear Noise Success |
Hear Noise Failure
| Hear Noise Success | |||||
| Surprise Failure | Surprise Failure | Surprise Failure | Surprise Failure | |||||
| Surprise! | Surprise! | Surprise! | Surprise! | Surprise! | Surprise! | Surprise! | Surprise! | |
| Anyone | - | - | - | 33.33% | 33.33% | - | 85.00% | 5.00% |
| Barbarian | - | - | - | 50.00% | 50.00% | - | 85.00% | 7.50% |
| Thief 1 | 2.00% | 6.80% | 0.40% | 30.00% | 33.33% | 20.00% | 68.00% | 4.00% |
| Thief 2 | 3.75% | 9.56% | 0.56% | 28.33% | 33.33% | 25.00% | 63.75% | 3.75% |
| Thief 3 | 6.00% | 11.90% | 0.70% | 26.66% | 33.33% | 30.00% | 59.50% | 3.50% |
| Thief 4 | 8.75% | 13.81% | 0.81% | 25.00% | 33.33% | 35.00% | 55.25% | 3.25% |
| Thief 5 | 12.00% | 15.30% | 0.90% | 23.33% | 33.33% | 40.00% | 51.00% | 3.00% |
| Thief 6 | 15.75% | 16.36% | 0.96% | 21.66% | 33.33% | 45.00% | 46.75% | 2.75% |
| Thief 7 | 24.75% | 17.21% | 1.01% | 18.33% | 33.33% | 55.00% | 38.25% | 2.25% |
| Thief 8 | 35.75% | 16.36% | 0.96% | 15.00% | 33.33% | 65.00% | 29.75% | 1.75% |
| Thief 9 | 48.75% | 13.81% | 0.81% | 11.67% | 33.33% | 75.00% | 21.25% | 1.25% |
| Thief 10 | 63.75% | 9.56% | 0.56% | 8.33% | 33.33% | 85.00% | 12.75% | 0.75% |
| Thief 11 | 80.75% | 3.61% | 0.21% | 5.00% | 33.33% | 95.00% | 4.25% | 0.25% |
| Thief 12 | 85.50% | 3.83% | 0.22% | 3.33% | 33.33% | 95.00% | 4.25% | 0.25% |
| Thief 13 | 95.00% | 0.00% | 0.00% | 1.67% | 33.33% | 100.00% | 0.00% | 0.00% |
| Thief 14 | 100.00% | 0.00% | 0.00% | 0.00% | 33.33% | 100.00% | 0.00% | 0.00% |
This is a Plinko game of possible ways to get surprise on someone. Drop from Attentive Target to a Hide Success to a Move Silent Failure to a Hear Noise Failure, and you know your 5th level Thief has a 15.3% chance to get surprise in that particular situation.
Check out Thief 14. Note how there's a bunch of 0% chances in there - that's the chance to get into that particular situation - we never do, because the Thief does not fail her checks at that level. That leads us to our next table.
The thing about percentages is that different choices at different rates of success to get to the same result are additive - so we can simplify this further, if we don't care how the result was had:
| Target Without Alertness | Target Has Alertness | |||||
| Attentive Target | Inattentive Target | Attentive Target | Inattentive Target | |||
| Concealment | No Concealment | Concealment | No Concealment | |||
| Anyone | 33.33% | 33.33% | 90.00% | 16.67% | 16.67% | 70.83% |
| Barbarian | 50.00% | 50.00% | 92.50% | 33.33% | 33.33% | 76.67% |
| Thief 1 | 39.20% | 33.33% | 92.00% | 22.67% | 16.67% | 76.67% |
| Thief 2 | 42.21% | 33.33% | 92.50% | 25.89% | 16.67% | 78.13% |
| Thief 3 | 45.26% | 33.33% | 93.00% | 29.25% | 16.67% | 79.58% |
| Thief 4 | 48.37% | 33.33% | 93.50% | 32.76% | 16.67% | 81.04% |
| Thief 5 | 51.53% | 33.33% | 94.00% | 36.42% | 16.67% | 82.50% |
| Thief 6 | 54.74% | 33.33% | 94.50% | 40.22% | 16.67% | 83.96% |
| Thief 7 | 61.31% | 33.33% | 95.50% | 48.26% | 16.67% | 86.88% |
| Thief 8 | 68.07% | 33.33% | 96.50% | 56.89% | 16.67% | 89.79% |
| Thief 9 | 75.04% | 33.33% | 97.50% | 66.09% | 16.67% | 92.71% |
| Thief 10 | 82.21% | 33.33% | 98.50% | 75.89% | 16.67% | 95.63% |
| Thief 11 | 89.57% | 33.33% | 99.50% | 86.26% | 16.67% | 98.54% |
| Thief 12 | 92.88% | 33.33% | 99.50% | 90.35% | 16.67% | 98.54% |
| Thief 13 | 96.67% | 33.33% | 100.00% | 95.83% | 16.67% | 100.00% |
| Thief 14 | 100.00% | 33.33% | 100.00% | 100.00% | 16.67% | 100.00% |
As Judge, I have exactly three decisions - does the target have Alertness, is the target Attentive, is Concealment available - then I roll my percentile single surprise roll for that particular situation or round of movement.
This brings out some interesting things. Barbarian's Naturally Stealthy is a heck of a bonus - pushing the Barbarian's chance to surprise a foe up to the same level as a 5th level Thief sneaking her heart out. (we can safely assume the Barbarian always fails his Hide In Shadows check, hence he has his normal chance to surprise the opponent).
If I really wanted to know how the thief managed to surprise her target, I could set up a table assigning ranges to different percent spreads, drawing from the first table. If I was willing to give up some resolution on the results, I could drag this back down into a d20 table (which I'll probably do before I actually use this).
Since I have the spreadsheets up, I can take a moment to look at a few different possiblities. In the thread on Autarch's board that spawned all this, Alex posted a set of house rules to improve the thief's chances via equipment bonuses and encumberance advantages.
All in all, the maximal bonus a thief can get to Hide in Shadows and Move Silently is +6 each. What's that look like?
| Target Without Alertness | Target Has Alertness | |||||
| Attentive Target | Inattentive Target | Attentive Target | Inattentive Target | |||
| Concealment | No Concealment | Concealment | No Concealment | |||
| Anyone | 33.33% | 33.33% | 76.67% | 16.67% | 16.67% | 70.83% |
| Barbarian | 50.00% | 50.00% | 82.50% | 33.33% | 33.33% | 76.67% |
| Thief 1 | 55.33% | 33.33% | 88.33% | 44.17% | 16.67% | 85.42% |
| Thief 2 | 58.61% | 33.33% | 89.50% | 48.26% | 16.67% | 86.88% |
| Thief 3 | 62.00% | 33.33% | 90.67% | 52.50% | 16.67% | 88.33% |
| Thief 4 | 65.51% | 33.33% | 91.83% | 56.89% | 16.67% | 89.79% |
| Thief 5 | 69.13% | 33.33% | 93.00% | 61.42% | 16.67% | 91.25% |
| Thief 6 | 72.87% | 33.33% | 94.17% | 66.09% | 16.67% | 92.71% |
| Thief 7 | 80.71% | 33.33% | 96.50% | 75.89% | 16.67% | 95.63% |
| Thief 8 | 89.01% | 33.33% | 98.83% | 86.26% | 16.67% | 98.54% |
| Thief 9 | 96.67% | 33.33% | 100.00% | 95.83% | 16.67% | 100.00% |
| Thief 10 | 100.00% | 33.33% | 100.00% | 100.00% | 16.67% | 100.00% |
| Thief 11 | 100.00% | 33.33% | 100.00% | 100.00% | 16.67% | 100.00% |
| Thief 12 | 100.00% | 33.33% | 100.00% | 100.00% | 16.67% | 100.00% |
| Thief 13 | 100.00% | 33.33% | 100.00% | 100.00% | 16.67% | 100.00% |
| Thief 14 | 100.00% | 33.33% | 100.00% | 100.00% | 16.67% | 100.00% |
Quite a bit better. A city thief who's not running out of armor oil in the middle of a dungeon can make a pretty good go of things right off, beating the Barbarian immediately. That table also models somewhat what would happen if a DEX 18 Thief was allowed to add her bonus to the rolls, and had taken the two proficiencies improving the skills, for a +5 total to each.
Moving on, what happens if we let Naturally Stealthy be a general proficiency, so anyone can take it, including thieves and other folks with stealth skills?
| Target Without Alertness | Target Has Alertness | |||||
| Attentive Target | Inattentive Target | Attentive Target | Inattentive Target | |||
| Concealment | No Concealment | Concealment | No Concealment | |||
| Anyone | 50.00% | 50.00% | 92.50% | 33.33% | 33.33% | 76.67% |
| Barbarian | 50.00% | 50.00% | 92.50% | 33.33% | 33.33% | 76.67% |
| Thief 1 | 54.40% | 50.00% | 94.00% | 38.13% | 33.33% | 81.33% |
| Thief 2 | 56.66% | 50.00% | 94.38% | 40.71% | 33.33% | 82.50% |
| Thief 3 | 58.95% | 50.00% | 94.75% | 43.40% | 33.33% | 83.67% |
| Thief 4 | 61.28% | 50.00% | 95.13% | 46.21% | 33.33% | 84.83% |
| Thief 5 | 63.65% | 50.00% | 95.50% | 49.13% | 33.33% | 86.00% |
| Thief 6 | 66.06% | 50.00% | 95.88% | 52.17% | 33.33% | 87.17% |
| Thief 7 | 70.98% | 50.00% | 96.63% | 58.61% | 33.33% | 89.50% |
| Thief 8 | 76.06% | 50.00% | 97.38% | 65.51% | 33.33% | 91.83% |
| Thief 9 | 81.28% | 50.00% | 98.13% | 72.87% | 33.33% | 94.17% |
| Thief 10 | 86.66% | 50.00% | 98.88% | 80.71% | 33.33% | 96.50% |
| Thief 11 | 92.18% | 50.00% | 99.63% | 89.01% | 33.33% | 98.83% |
| Thief 12 | 94.66% | 50.00% | 99.63% | 92.28% | 33.33% | 98.83% |
| Thief 13 | 97.50% | 50.00% | 100.00% | 96.67% | 33.33% | 100.00% |
| Thief 14 | 100.00% | 50.00% | 100.00% | 100.00% | 33.33% | 100.00% |
Gives a good improvement, but doesn't have that sudden jump at the end that happens with the equipment/encumberance rules. It'd be a heck of a lot better than the proficiencies that give +2 to the skills.
Let's do a couple more question-answerings. What happens if we let anyone try to Hide in Shadows or Move Silently, at one less point on the die than a level 1 Thief?
| Target Without Alertness | Target Has Alertness | |||||
| Attentive Target | Inattentive Target | Attentive Target | Inattentive Target | |||
| Concealment | No Concealment | Concealment | No Concealment | |||
| Anyone | 36.24% | 33.33% | 91.50% | 19.59% | 16.67% | 75.21% |
| Barbarian | 52.18% | 50.00% | 93.63% | 35.67% | 33.33% | 80.17% |
| Thief 1 | 39.20% | 33.33% | 92.00% | 22.67% | 16.67% | 76.67% |
| Thief 2 | 42.21% | 33.33% | 92.50% | 25.89% | 16.67% | 78.13% |
| Thief 3 | 45.26% | 33.33% | 93.00% | 29.25% | 16.67% | 79.58% |
| Thief 4 | 48.37% | 33.33% | 93.50% | 32.76% | 16.67% | 81.04% |
| Thief 5 | 51.53% | 33.33% | 94.00% | 36.42% | 16.67% | 82.50% |
| Thief 6 | 54.74% | 33.33% | 94.50% | 40.22% | 16.67% | 83.96% |
| Thief 7 | 61.31% | 33.33% | 95.50% | 48.26% | 16.67% | 86.88% |
| Thief 8 | 68.07% | 33.33% | 96.50% | 56.89% | 16.67% | 89.79% |
| Thief 9 | 75.04% | 33.33% | 97.50% | 66.09% | 16.67% | 92.71% |
| Thief 10 | 82.21% | 33.33% | 98.50% | 75.89% | 16.67% | 95.63% |
| Thief 11 | 89.57% | 33.33% | 99.50% | 86.26% | 16.67% | 98.54% |
| Thief 12 | 92.88% | 33.33% | 99.50% | 90.35% | 16.67% | 98.54% |
| Thief 13 | 96.67% | 33.33% | 100.00% | 95.83% | 16.67% | 100.00% |
| Thief 14 | 100.00% | 33.33% | 100.00% | 100.00% | 16.67% | 100.00% |
A couple percent point improvement for the non-thief classes; theoretically cheap to implement if you're OK with using this table.
One more - there's a few thoughts floating around about combining Move Silently and Hide In Shadows into one single 'Stealth' or 'Skulking' skill roll. What happens if we remove the barrier to success that is requiring two successful rolls?
| Attentive Target |
Inattentive Target
| |||||||
| Concealment |
No Concealment
| |||||||
Stealth Failure (Same as No Concealment)
| ||||||||
Stealth Successful
| Stealth Failure |
Stealth Successful
| Stealth Failure | |||||
Hear Noise Failure
| Hear Noise Success |
Hear Noise Failure
| Hear Noise Success | |||||
| Surprise Failure | Surprise Failure | Surprise Failure | Surprise Failure | |||||
| Surprise! | Surprise! | Surprise! | Surprise! | Surprise! | Surprise! | Surprise! | Surprise! | |
| Anyone | 15.00% | 72.25% | 4.25% | 33.33% | 33.33% | 15.00% | 72.25% | 4.25% |
| Barbarian | 15.00% | 72.25% | 6.38% | 50.00% | 50.00% | 15.00% | 72.25% | 6.38% |
| Thief 1 | 20.00% | 68.00% | 4.00% | 33.33% | 33.33% | 20.00% | 68.00% | 4.00% |
| Thief 2 | 25.00% | 63.75% | 3.75% | 33.33% | 33.33% | 25.00% | 63.75% | 3.75% |
| Thief 3 | 30.00% | 59.50% | 3.50% | 33.33% | 33.33% | 30.00% | 59.50% | 3.50% |
| Thief 4 | 35.00% | 55.25% | 3.25% | 33.33% | 33.33% | 35.00% | 55.25% | 3.25% |
| Thief 5 | 40.00% | 51.00% | 3.00% | 33.33% | 33.33% | 40.00% | 51.00% | 3.00% |
| Thief 6 | 45.00% | 46.75% | 2.75% | 33.33% | 33.33% | 45.00% | 46.75% | 2.75% |
| Thief 7 | 55.00% | 38.25% | 2.25% | 33.33% | 33.33% | 55.00% | 38.25% | 2.25% |
| Thief 8 | 65.00% | 29.75% | 1.75% | 33.33% | 33.33% | 65.00% | 29.75% | 1.75% |
| Thief 9 | 75.00% | 21.25% | 1.25% | 33.33% | 33.33% | 75.00% | 21.25% | 1.25% |
| Thief 10 | 85.00% | 12.75% | 0.75% | 33.33% | 33.33% | 85.00% | 12.75% | 0.75% |
| Thief 11 | 95.00% | 4.25% | 0.25% | 33.33% | 33.33% | 95.00% | 4.25% | 0.25% |
| Thief 12 | 95.00% | 4.25% | 0.25% | 33.33% | 33.33% | 95.00% | 4.25% | 0.25% |
| Thief 13 | 100.00% | 0.00% | 0.00% | 33.33% | 33.33% | 100.00% | 0.00% | 0.00% |
| Thief 14 | 100.00% | 0.00% | 0.00% | 33.33% | 33.33% | 100.00% | 0.00% | 0.00% |
That's quite a boost! A failure in Stealth gets boiled down to being the same as having no concealment, and Hear Noise becomes a much less effective gateway. Our combined tables look like so:
| Target Without Alertness | Target Has Alertness | |||||
| Attentive Target | Inattentive Target | Attentive Target | Inattentive Target | |||
| Concealment | No Concealment | Concealment | No Concealment | |||
| Anyone | 91.50% | 33.33% | 91.50% | 75.21% | 16.67% | 75.21% |
| Barbarian | 93.63% | 50.00% | 93.63% | 80.17% | 33.33% | 80.17% |
| Thief 1 | 92.00% | 33.33% | 92.00% | 76.67% | 16.67% | 76.67% |
| Thief 2 | 92.50% | 33.33% | 92.50% | 78.13% | 16.67% | 78.13% |
| Thief 3 | 93.00% | 33.33% | 93.00% | 79.58% | 16.67% | 79.58% |
| Thief 4 | 93.50% | 33.33% | 93.50% | 81.04% | 16.67% | 81.04% |
| Thief 5 | 94.00% | 33.33% | 94.00% | 82.50% | 16.67% | 82.50% |
| Thief 6 | 94.50% | 33.33% | 94.50% | 83.96% | 16.67% | 83.96% |
| Thief 7 | 95.50% | 33.33% | 95.50% | 86.88% | 16.67% | 86.88% |
| Thief 8 | 96.50% | 33.33% | 96.50% | 89.79% | 16.67% | 89.79% |
| Thief 9 | 97.50% | 33.33% | 97.50% | 92.71% | 16.67% | 92.71% |
| Thief 10 | 98.50% | 33.33% | 98.50% | 95.63% | 16.67% | 95.63% |
| Thief 11 | 99.50% | 33.33% | 99.50% | 98.54% | 16.67% | 98.54% |
| Thief 12 | 99.50% | 33.33% | 99.50% | 98.54% | 16.67% | 98.54% |
| Thief 13 | 100.00% | 33.33% | 100.00% | 100.00% | 16.67% | 100.00% |
| Thief 14 | 100.00% | 33.33% | 100.00% | 100.00% | 16.67% | 100.00% |
That's...excessive. The system sort of falls apart, because Hear Noise's high failure rate is really relying on the combined low percentage chance of both Hide in Shadows and Move Silently needing to be successful - since we don't have a check for "seeing something" other than determining the alertness level of the target. You'd almost have to give being "alert" a throw (like d20 did with Spot) or transmogrify Hear Noise into a general "Notice" throw at a better chance of success.
Even if you reversed Hear Noise so that it succeeded on a throw of 5+, you're still going to have a straight improvement from a base of around 54%, rather than the gradual, curved improvement afforded by requiring two separate rolls.
You may have to then fall back to opposed rolls. Not sure - I'm gonna let that lie outside the scope of this post.
What's the takeaway?
If you look at it as a whole process, it's not as bad as the numbers on the Thief table make it seem. Just being a Thief gets you a better chance to surprise an opponent than a normal person right off. From that view, it's no better or worse than the fighter's Attack Throw at level one - better than a normal man, but not superheroic by any means.
And, for those that want to fiddle, even as much as a +6 bonus doesn't end up being much more than a 20% improvement level-by-level during the first ~9 levels - and letting anyone attempt to sneak at a tick worse than a level 1 Thief doesn't change things much.
On the other hand, combining Move Silently and Hide in Shadows certainly makes a change for the worse (depending on your view) as it relegates Hear Noise to a much lesser role.
And, for those that want to fiddle, even as much as a +6 bonus doesn't end up being much more than a 20% improvement level-by-level during the first ~9 levels - and letting anyone attempt to sneak at a tick worse than a level 1 Thief doesn't change things much.
On the other hand, combining Move Silently and Hide in Shadows certainly makes a change for the worse (depending on your view) as it relegates Hear Noise to a much lesser role.
.
