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Systems & Settings => Rolemaster => Topic started by: Druss_the_Legend on November 27, 2016, 12:57:14 AM

Title: Ambush - is it too powerful?
Post by: Druss_the_Legend on November 27, 2016, 12:57:14 AM
what do you think about the ambush skill?
it seems really good at 10 ranks or more. when combined with rear and surprise modifiers it seems a bit over powered imo.

thoughts?
Title: Re: Ambush - is it too powerful?
Post by: Warl on November 27, 2016, 02:11:48 AM
not really...it is only, at 10 ranks, a 10 point swing on the crit table.

it shows knowledge of target movement and they do have to have surprise
Title: Re: Ambush - is it too powerful?
Post by: jdale on November 27, 2016, 09:56:51 AM
If you think it's too powerful, it's on you as the GM to make the character really work for that surprise attack. The easier it is to achieve a surprise attack, the more potent ambush is.
Title: Re: Ambush - is it too powerful?
Post by: Druss_the_Legend on November 28, 2016, 04:39:06 PM
If you think it's too powerful, it's on you as the GM to make the character really work for that surprise attack. The easier it is to achieve a surprise attack, the more potent ambush is.

agreed. i have a burglar who has shadow hop spell that essentially turns him into nightcrawler from the x-men at night.
i was lenient on orientation checks by him and his targets last time. Will not be quite so easy next time.
Title: Re: Ambush - is it too powerful?
Post by: mtpnj on November 28, 2016, 04:43:13 PM
Don't forget snipping from one of the companions.  That is even more powerful as it is with a bow from a distance.  Never even get seen.  I have a character with about 15 ranks in snipping which is almost a 50% automatic kill.  51 roll plus 15 ranks gets you to 66.
Title: Re: Ambush - is it too powerful?
Post by: Peter R on November 29, 2016, 02:20:20 AM
Don't forget snipping from one of the companions.  That is even more powerful as it is with a bow from a distance.  Never even get seen.  I have a character with about 15 ranks in snipping which is almost a 50% automatic kill.  51 roll plus 15 ranks gets you to 66.

I don't think the sniping skill was thought out very well. In a high tech game then it would be viable but with bows etc., it is a non starter imho.
Title: Re: Ambush - is it too powerful?
Post by: RandalThor on November 29, 2016, 04:57:50 AM
I thought that '66' had to be rolled naturally, that none of the skills/spells/abilities can be used to push the critical there. Is that not the case with RMU?
Title: Re: Ambush - is it too powerful?
Post by: Spectre771 on November 29, 2016, 08:07:57 AM
I thought that '66' had to be rolled naturally, that none of the skills/spells/abilities can be used to push the critical there. Is that not the case with RMU?

That's the 'rule' we've always used with RM2.  There were certain 'natural numbers' that had to be rolled and could not be modified to get.  The 66 on a crit was one such roll.  I don't recall reading anything in RMU that stated whether that was allowed.
Title: Re: Ambush - is it too powerful?
Post by: jdale on November 29, 2016, 10:45:16 AM
There's nothing in RMSS/RMFRP forbidding you from modifying the roll to a 66, either. It is explicit that you can modify the roll by any amount up to your number of ranks, up or down. And I just checked in the original Character Law & Campaign Law, the text is the same there.

Treating a 66 result as UM 66, so you can't use Ambush to achieve it, does limit the lethality of Ambush and personally I would be inclined to play that way, but I suspect doing so is a house rule in every edition of RM.

Title: Re: Ambush - is it too powerful?
Post by: intothatdarkness on November 29, 2016, 12:08:19 PM
Don't forget snipping from one of the companions.  That is even more powerful as it is with a bow from a distance.  Never even get seen.  I have a character with about 15 ranks in snipping which is almost a 50% automatic kill.  51 roll plus 15 ranks gets you to 66.

I don't think the sniping skill was thought out very well. In a high tech game then it would be viable but with bows etc., it is a non starter imho.

Sniping the way RM has dealt with it has never been very good, IMO. I've got house rules dealing with it, but to really make sniping effective you need crit tables broken out by hit location.
Title: Re: Ambush - is it too powerful?
Post by: Peter R on November 29, 2016, 12:30:45 PM
Don't forget snipping from one of the companions.  That is even more powerful as it is with a bow from a distance.  Never even get seen.  I have a character with about 15 ranks in snipping which is almost a 50% automatic kill.  51 roll plus 15 ranks gets you to 66.

I just don't use that skill, not in a fantasy setting and for SF I am using HARP SF.

I don't think the sniping skill was thought out very well. In a high tech game then it would be viable but with bows etc., it is a non starter imho.

Sniping the way RM has dealt with it has never been very good, IMO. I've got house rules dealing with it, but to really make sniping effective you need crit tables broken out by hit location.
Title: Re: Ambush - is it too powerful?
Post by: Peter R on November 29, 2016, 12:33:41 PM
There's nothing in RMSS/RMFRP forbidding you from modifying the roll to a 66, either. It is explicit that you can modify the roll by any amount up to your number of ranks, up or down. And I just checked in the original Character Law & Campaign Law, the text is the same there.

Treating a 66 result as UM 66, so you can't use Ambush to achieve it, does limit the lethality of Ambush and personally I would be inclined to play that way, but I suspect doing so is a house rule in every edition of RM.

In the RMC combat companion critical tables there are two 66 results. An UM66 and 66-70 so this is built in.
Title: Re: Ambush - is it too powerful?
Post by: jdale on November 29, 2016, 06:24:28 PM
Interesting, I had not seen that.
Title: Re: Ambush - is it too powerful?
Post by: Warl on November 29, 2016, 07:07:09 PM
Posted this in the wrong thread

another couple house rules option, to help limit sniping and ambush:

#1 bonus is reduced by level of target

#2 limit use of ambush to required anatomy or biology skill. you only get to use a % of ranks bonus to adjust = to % of anatomy/biology skill for that race.
Title: Re: Ambush - is it too powerful?
Post by: Peter R on November 30, 2016, 02:20:12 AM
Interesting, I had not seen that.

This is what a combat table looks like with the UM66 critical.

(http://www.rolemasterblog.com/wp-content/uploads/2015/10/bash-with-ten-at-types.png)
Title: Re: Ambush - is it too powerful?
Post by: Ecthelion on November 30, 2016, 04:49:52 AM
I thought that '66' had to be rolled naturally, that none of the skills/spells/abilities can be used to push the critical there. Is that not the case with RMU?
As was explained above modifying the roll to 66 using Ambush is not forbidden by the RM2 or RMSS/RMFRP rules. In fact I personally think that the 66 was deliberately added to the critical tables to be used with Ambush.
Title: Re: Ambush - is it too powerful?
Post by: damage on November 30, 2016, 04:58:45 PM
I run a high-level RMFRP campaign with some characters having 30+ ranks in Ambush. So yes, as it is I find it quite overpowered, and have had to introduce some house rules to tone it down...

1. There's not one Ambush skill, there's several. Knowing how to Ambush a Human doesn't translate into knowing how to Ambush a Ghost, for example. I have skills in my game for Ambush : Humanoids (the default Ambush skill), Ambush : Undead, Ambush : Demonic etc. Some characters develop several of these skills, some just one.

2. No Sniping. Ambush is with melee weapons only. For a while I allowed point-blank Ambush with missile weapons, but at higher levels that becomes too strong.

3.  I've also had the Nightcrawler-like character, which is why I rule that teleporting (leaving etc) does not change orientation unless spell mastered to do so. Makes it hard to jump and attack in the same round.

Regards,

 - David.
Title: Re: Ambush - is it too powerful?
Post by: Druss_the_Legend on November 30, 2016, 10:13:01 PM
I run a high-level RMFRP campaign with some characters having 30+ ranks in Ambush. So yes, as it is I find it quite overpowered, and have had to introduce some house rules to tone it down...

1. There's not one Ambush skill, there's several. Knowing how to Ambush a Human doesn't translate into knowing how to Ambush a Ghost, for example. I have skills in my game for Ambush : Humanoids (the default Ambush skill), Ambush : Undead, Ambush : Demonic etc. Some characters develop several of these skills, some just one.

2. No Sniping. Ambush is with melee weapons only. For a while I allowed point-blank Ambush with missile weapons, but at higher levels that becomes too strong.

3.  I've also had the Nightcrawler-like character, which is why I rule that teleporting (leaving etc) does not change orientation unless spell mastered to do so. Makes it hard to jump and attack in the same round.

Regards,

 - David.

thanks for sharing these. im probably going to use the same restriction you have for nightcrawler style attacks, its too strong otherwise. without a restriction like this they can potentially combo-off and keep dropping/killing guys every round. you have given them a chance to master the spell is they invest dev points so thats very fair way of dealing with it imo.
Title: Re: Ambush - is it too powerful?
Post by: Spectre771 on December 01, 2016, 10:56:02 AM

As was explained above modifying the roll to 66 using Ambush is not forbidden by the RM2 or RMSS/RMFRP rules. In fact I personally think that the 66 was deliberately added to the critical tables to be used with Ambush.

I've been thinking about this since the thread came to be, and looking back at the gaming sessions we've had over the decades, it would seem this is exactly why "66" was stuck in the middle of the crit tables.  Looking at it with fresh eyes and fresh opinions on the topic, it's given me a new perspective.  We always said (i.e.: house ruled) the 66 had to be an UM because it was so powerful but without this magic number, Ambush is only used to increase the crit roll to hopefully get to the next threshold on the crit table.  Maybe the 85-93 category becomes the 94-100 category* and gets the better result. 

*-I can't recall the exact numbers, just using it as an example here.

The crits can be modified DOWN by Ambush skill and the way we explained it was "maybe you don't want to kill the target, just ambush to incapacitate" so you can modify your high crit to a lower value and hopefully get a less deadly, which we did quite often.  Funnily enough, it didn't always work; high crit, but Ambush skill just not good enough to avoid killing the target.

However, we also used the Ambush skill to set up a successful ambush situation, so this is a skill that we got double use from and it added value to DP investment.  We removed the 66 kill but allowed it as a bonus for setting an ambush in addition to modifying the crit roll.  Again, it was all house ruled, but I think I'll be removing that house rule now.

Title: Re: Ambush - is it too powerful?
Post by: rdanhenry on December 02, 2016, 08:50:03 AM
3.  I've also had the Nightcrawler-like character, which is why I rule that teleporting (leaving etc) does not change orientation unless spell mastered to do so. Makes it hard to jump and attack in the same round.

In RMU, teleportation is explicitly noisy, so except for Magents (with a quieter version) or Absurd Spell Mastery, you'd be giving up surprise by teleporting to your target.
Title: Re: Ambush - is it too powerful?
Post by: MurderByNumbers on December 02, 2016, 06:02:36 PM
(https://s11.postimg.org/hx46emvfj/image.jpg) (https://postimg.org/image/hx46emvfj/)

(https://s15.postimg.org/3mwk267w7/image.jpg) (https://postimg.org/image/3mwk267w7/)

 :P
Title: Re: Ambush - is it too powerful?
Post by: MurderByNumbers on December 02, 2016, 07:32:26 PM
self removed  :o
Title: Re: Ambush - is it too powerful?
Post by: jdale on December 02, 2016, 10:29:00 PM
Ok, I don't know about Ambush, but Precision is definitely too powerful.
Title: Re: Ambush - is it too powerful?
Post by: MurderByNumbers on December 02, 2016, 11:10:34 PM
Ok, I don't know about Ambush, but Precision is definitely too powerful.

Its a talent which allows you to roll for an ambush maneuver on every attack.

Keep in mind ambush rule specifically states if a target is already in melee ambush is reduced by 1/2
Title: Re: Ambush - is it too powerful?
Post by: jdale on December 03, 2016, 01:35:05 AM
Compare that bonus, which typically would be equal to your level, to other bonuses to criticals. For example, in RMSS's Martial Arts Companion, you could make an advanced martial arts style, which in many cases would be a restricted skill (half development ranks), devoting half of the style's benefits (30 out of 60 style points) to getting a bonus of just +2 on your critical rolls.
Title: Re: Ambush - is it too powerful?
Post by: MurderByNumbers on December 03, 2016, 06:00:57 AM
Compare that bonus, which typically would be equal to your level, to other bonuses to criticals. For example, in RMSS's Martial Arts Companion, you could make an advanced martial arts style, which in many cases would be a restricted skill (half development ranks), devoting half of the style's benefits (30 out of 60 style points) to getting a bonus of just +2 on your critical rolls.

well what do you think about this..
Two Weapon Combat
Ambush
Precision
Magical Haste
Physical Haste (total 300% action, still restricted to 3 actions per round)
(https://s18.postimg.org/om9sxtkp1/image.jpg) (https://postimg.org/image/om9sxtkp1/)
so critical is +1 severity
(https://s14.postimg.org/hanud23xp/image.jpg) (https://postimg.org/image/hanud23xp/)
+1 critical of equal severity
(https://s13.postimg.org/wj0fykg7n/image.jpg) (https://postimg.org/image/wj0fykg7n/)
Triple concussive damage (just for some more cheese)

Ambush attempt (assume success)
6 strikes (assume all crit)
6 criticals, + 6 additional criticals from weapon.
12 criticals of +1 severity due to weapon
3x concussive damage due to weapon
All criticals being modified by +/-  the appropriate ambush ranks

pew..pew.. thats the assassin's dream isnt it? couple problems though..
1. will your gm allow it?
2. if they do you better watch your back because theres a good chance the same will be coming at you eventually



im just playing rules lawyer devil's advocate for fun ;) please don't take it too seriously
Title: Re: Ambush - is it too powerful?
Post by: vector on December 03, 2016, 05:43:29 PM
(https://s11.postimg.org/hx46emvfj/image.jpg) (https://postimg.org/image/hx46emvfj/)

(https://s15.postimg.org/3mwk267w7/image.jpg) (https://postimg.org/image/3mwk267w7/)

 :P

Long ago I once allowed a character to take the Precision talent...ONCE!
Title: Re: Ambush - is it too powerful?
Post by: arakish on December 04, 2016, 07:14:15 AM
Topic Question: Ambush - is it too powerful?

I have been browsing through this thread for some time.

My First Thought Answer: NO!  Ambush is not too powerful.  By its very nature, Ambush is meant to kill/destroy as immediately as possible.

However, as I browsed the thread, there have been some good points made.


If you think it's too powerful, it's on you as the GM to make the character really work for that surprise attack. The easier it is to achieve a surprise attack, the more potent ambush is.

This I have to agree with completely.  It is ALWAYS the GM's province to temper anything s/he thinks causes any unbalance in her/his game.


Don't forget snipping from one of the companions.  That is even more powerful as it is with a bow from a distance.  Never even get seen.  I have a character with about 15 ranks in snipping which is almost a 50% automatic kill.  51 roll plus 15 ranks gets you to 66.

I don't think the sniping skill was thought out very well. In a high tech game then it would be viable but with bows etc., it is a non starter imho.

Another point I completely agree with.  That is why in all my worlds, "sniping" was disallowed from my skills listing.  OR, if I did allow the skill, I redifined it as a skill that ONLY increases the accuracy of the ambush shot.  IOW, you had to roll for sniping skill first to get how accurate your ambush shot is (number results on MM table dictates the percentage of ambush bonus you can use).  Due to this redefining of the "sniping" skill, most of my players never developed it.


I run a high-level RMFRP campaign with some characters having 30+ ranks in Ambush. So yes, as it is I find it quite overpowered, and have had to introduce some house rules to tone it down...

1. There's not one Ambush skill, there's several. Knowing how to Ambush a Human doesn't translate into knowing how to Ambush a Ghost, for example. I have skills in my game for Ambush : Humanoids (the default Ambush skill), Ambush : Undead, Ambush : Demonic etc. Some characters develop several of these skills, some just one.

2. No Sniping. Ambush is with melee weapons only. For a while I allowed point-blank Ambush with missile weapons, but at higher levels that becomes too strong.

3.  I've also had the Nightcrawler-like character, which is why I rule that teleporting (leaving etc) does not change orientation unless spell mastered to do so. Makes it hard to jump and attack in the same round.

Regards,

 - David.


Hallelujah!  Somebody else did the same thing I did.


Ok, I don't know about Ambush, but Precision is definitely too powerful.

One reason I disallow this talent.


well what do you think about this..
Two Weapon Combat
Ambush
Precision
Magical Haste
Physical Haste (total 300% action, still restricted to 3 actions per round)

Ambush attempt (assume success)
6 strikes (assume all crit)
6 criticals, + 6 additional criticals from weapon.
12 criticals of +1 severity due to weapon
3x concussive damage due to weapon
All criticals being modified by +/-  the appropriate ambush ranks

pew..pew.. thats the assassin's dream isnt it? couple problems though..
1. will your gm allow it?
2. if they do you better watch your back because theres a good chance the same will be coming at you eventually

im just playing rules lawyer devil's advocate for fun ;) please don't take it too seriously


IMHO (highlighted), my answer is, "7734, NO!"


Long ago I once allowed a character to take the Precision talent...ONCE!

Funny.  I never have allowed Precision. ;)



Now for some of my opinions.  In answer to the original question: I do NOT believe the skill "Ambush" itself is too powerful.  Ambush by its very nature is a very powerful attack.  However, if GMed properly, Ambush is good for ONLY the first shot (first round).  After it is sprung, Ambush never again plays into the "tactical sequence" (unless, during melee, a person can "sneak" behind someone else and "backstab").  IOW, once that first shot is taken, the "surprise" factor is no longer in effect.  However, the disorienting effect and confusion caused by that "first surprise shot" can hypothetically last more one or more rounds afterwards.  Possibly allowing more "ambush" shots but at half effect.

I do believe the skill "ambush" can be made to be "too powerful" by rules rapists as shown by MurderByNumbers example above.  [Don't worry, MurderByNumbers, I did take it in fun.  Good example!]  His example is a very good one showing why GMs MUST always be on their toes and fully scrutinize anything their players come up with in character creation.

rmfr
Title: Re: Ambush - is it too powerful?
Post by: Druss_the_Legend on December 07, 2016, 01:08:41 AM
so when this skill is rolled the ambusher still needs to make a static action to use ambush right?
Title: Re: Ambush - is it too powerful?
Post by: MurderByNumbers on December 07, 2016, 04:45:37 AM
so when this skill is rolled the ambusher still needs to make a static action to use ambush right?

yes, every time. with negative modifiers to the ambush (depending on position and or parry vs the person trying to roll ambush)

So surprise
Roll for stalk
Roll for Ambush
Roll to hit
If successful ambush, and crit, modify by Full ranks if target not in combat. 1/2 ranks if target is in melee

No surprise (precision)
Roll for ambush with negative modifiers
Roll to hit
If Successful ambush and crit can modify by 1/2 ranks.

So lets say you have precision, +90on ambush, and you have to roll a 70+ to crit.
Fighting face to face without subtraction for parry.
-35, for ease here we'll say you need 110 + (100 is success, 111+ is successs)
So you're at +55, you need a 55+ to ambush
45% to ambush
30% to crit
13.5% chance that youll get an ambush and a crit off
lets say you have 18 ranks in ambush, already in melee thats +/- 9
and we'll say you're looking for a 61+, 61-9 = 52+ on the roll
48% the crit is a big impact with precision+ ambush vs 39% without precision.

Does it make an impact? certainly. Is it as game breaking as people try to make it out to be? No.

Please keep in mind how many additional points are sunk into this to improve the combat effectiveness of the character.. That are ONLY useful if a successful ambush goes of. Otherwise its wasted points. without precision it's very under powered. Especially if you make someone work so hard it rarely gets used. it's quite possible to make ambush a waste of points and time. If a player can only ever get it off once, they waste rounds trying to get into position to use it etc. Those are rounds they could of just gone into combat normally, swung at the target, and picked up an extra 1/2/3 etc crits over the duration of the fight. As well as the positional/tactical advantages of having another player in the fight earlier in the combat to control the flow... As well as points they could of put into something to improve their character in other ways, pick up level 1-3 spells to enhance? Pick up skills improving survival? any skill really...lol


note: please forgive the minor math inaccuracies... its close though.
Point was to just run the real numbers, compare the differences.
I think you'll really see how little of a difference it makes over the long run of fights.

is Ambush+precision powerful? Without a doubt.
Is Ambush powerful? Situationally, overall not really.
Title: Re: Ambush - is it too powerful?
Post by: jdale on December 07, 2016, 11:11:15 AM
There's some ambiguity about whether a maneuver roll is needed in RM2. It's definitely needed in RMSS/RMFRP, but not in RMU.
Title: Re: Ambush - is it too powerful?
Post by: Peter R on December 07, 2016, 04:29:56 PM
There's some ambiguity about whether a maneuver roll is needed in RM2. It's definitely needed in RMSS/RMFRP, but not in RMU.

In RMC you have to succeed with your Ambush skill before you can apply the Ambush ranks to a critical.
Title: Re: Ambush - is it too powerful?
Post by: Druss_the_Legend on December 07, 2016, 11:55:54 PM
There's some ambiguity about whether a maneuver roll is needed in RM2. It's definitely needed in RMSS/RMFRP, but not in RMU.

In RMC you have to succeed with your Ambush skill before you can apply the Ambush ranks to a critical.

so is this success roll a static action or moving manouvre? situations specific? could be either?
Title: Re: Ambush - is it too powerful?
Post by: Peter R on December 08, 2016, 01:56:01 AM
There's some ambiguity about whether a maneuver roll is needed in RM2. It's definitely needed in RMSS/RMFRP, but not in RMU.

In RMC you have to succeed with your Ambush skill before you can apply the Ambush ranks to a critical.

so is this success roll a static action or moving manouvre? situations specific? could be either?

Static action.
Title: Re: Ambush - is it too powerful?
Post by: MurderByNumbers on December 08, 2016, 12:40:44 PM
There's some ambiguity about whether a maneuver roll is needed in RM2. It's definitely needed in RMSS/RMFRP, but not in RMU.

In RMC you have to succeed with your Ambush skill before you can apply the Ambush ranks to a critical.

so is this success roll a static action or moving manouvre? situations specific? could be either?

^+1 to static

Don't forget.. if we're talking about ambush without being combined with the talent 'precision'
you're going to have to succeed in another static maneuver prior to attempting ambush.
"To use his Ambush skill a character must approach his foe undetected.."
Stalking roll first
(perhaps certain situations hiding if you are in a position that the enemy walks within melee range of where you're hiding?)

Title: Re: Ambush - is it too powerful?
Post by: Hurin on December 08, 2016, 01:03:56 PM
Am I correct that there currently is no 'Precision' talent in RMU? I hope so. It seems overpowered.

I haven't weighed in on Ambush because my players haven't used Ambush much, but I think it could be abused/overpowered. I think the suggestion that it has to be developed for each creature type would be an appropriate limit.
Title: Re: Ambush - is it too powerful?
Post by: Druss_the_Legend on December 08, 2016, 03:36:11 PM
so stalking roll or hiding roll
then static action using ambush
Title: Re: Ambush - is it too powerful?
Post by: vector on December 08, 2016, 04:25:08 PM
Hey guys, know something that's "overpowered" in real life? Answer: A trained killer striking with a deadly weapon from complete surprise!


I know, I know, "realism" vs. game balance, fun etc. Speaking of fun, some of the most fun I've had as a GM, and rare player, has been planning and running scenarios involving infiltration and assassinations. Some of my top favorite video games were the Thief series, and I'm currently in love with the Dishonored games (closest I can get to a Nightblade simulator LOL).


Like jdale wrote, the trick is making sure your players really work for that surprise. So I don't think the skill in and of itself is overpowerd, but it is one that a GM has to manage more closely than others.
Title: Re: Ambush - is it too powerful?
Post by: Warl on December 08, 2016, 08:02:03 PM
Hey guys, know something that's "overpowered" in real life? Answer: A trained killer striking with a deadly weapon from complete surprise!


I know, I know, "realism" vs. game balance, fun etc. Speaking of fun, some of the most fun I've had as a GM, and rare player, has been planning and running scenarios involving infiltration and assassinations. Some of my top favorite video games were the Thief series, and I'm currently in love with the Dishonored games (closest I can get to a Nightblade simulator LOL).


Like jdale wrote, the trick is making sure your players really work for that surprise. So I don't think the skill in and of itself is overpowerd, but it is one that a GM has to manage more closely than others.

I love the game "Thief"... The Whole series...
Title: Re: Ambush - is it too powerful?
Post by: MurderByNumbers on December 08, 2016, 09:38:30 PM
I would recommend instead of going off "feeling" "guessing"

Select a character level, determine the following
Weapon type (affects difficulty of ambush)
OB in said weapon
AT (affects difficulty of stalking)
Stalking skill
Ambush skill and of#ranks


Select an appropriate level opponent.
Determine their counter skills
Alertness/sense ambush/scouting awareness/observation etc
AT
etc

Keep track of how many DB you spend in stalking and ambush

Do some math, rolls needed at each step for success and what that translates into in regards to frequency (or odds) of ambush actually happening.
Did the +/- in the critical significantly alter the fight?
How many rounds are typically required to prep for the ambush?
How many concussive hits+crits do you on average per swing in a stand up fight?
Multiple the previous 2 together.
Did the additional benefit of ambush exceed this amount?
Out of how many fights do you get to use ambush?
This will give you numerical effectiveness comparisons...


DB Spent on Stalk/Ambush
Could you have spent them elsewhere for better utilization of DB?
Try pushing those points into something else, run a few combat numbers.
Was it more effective?

Guess another way to look at it is this..
The higher an ability is the less chance of said skill failing, we can all agree on this.
By increasing skill you increase the reliability of the skill in question.
By Introducing more skill checks you decrease reliability.
Ambush is essentially a DB investment into a situational use of 2 static maneuvers for a chance to increase reliability on the back end (the crit)

Fighter
OB Roll, Crit Roll.
-Roll To Hit, high reliability due to high modification
-Roll to Crit, low reliability due to no modification
Not many rolls, low chance to fail, very dependable application of damage and crits
-Higher OB allows for increased survivability through parry


Rogue type
-Stalk, Med-High reliability due to medium/high mod/situation
-Ambush, Med-high reliability due to medium/highmod/situation
-Roll to Hit, High reliability but less than fighter (rogue type will never = a true fighter in OB)
-Ambush Roll to Crit, Low-medium reliability due crit modification. due to low/medium modification
More rolls, more chances to fail, if you successfully get to Crit, higher reliability of outcome.
-less survivability from lower AT, and Less OB for parrying


that turned into a much longer post than i intended lol... point i'm trying to make is. I would recommend running the numbers and looking at it objectively and not going off feeling/gut reaction to watching a rogue basically remove a npc from a fight with a crit.