Preparation Required clarification: Roll before or after?

[JCurwen3]

If an ability has Preparation Required, and also requires some activation roll that you have to make in order to successfully activate the ability, do you roll before or after the prep time?

Basically, if you'd roll before, then that'd mean you would know you'd succeed if your preparations aren't interrupted, and if after then you could spend time time preparing and then find out it was all for nought if you botch the roll at the end. How is it supposed to work?

[Snargash Moonclaw]

Roll at the end. Whether you make a skill roll at the end of a one second action or one that takes more time, you won't know if you've succeeded until you finish the whole thing - which generally includes the prep. (Compare to spells with multi-turn casting times.) Optional prep actions, e.g., Symbol Drawing to enhance a subsequent ritual are often made at the end of the prep action since failure simply means no bonus. It would be perfectly legitimate to require simultaneous rolls (with different colored, or otherwise distinct sets of dice) and apply the results of one roll to the other since you might not know how well you prepped until you perform the final action - but these cases are for incorporating variables. (If I required rolls in this fashion I would at least give some chance to "proof" the prep work before the final stage.) Required Prep is generally a Go/No-go determiner. Of course, given the scope of cases in GURPS, subsequent posters may well point out exceptions which I haven't thought of in answering you. When in doubt, I suggest use the above as a default and consider merits of specific cases as they arise.

[JCurwen3]

Originally Posted by Snargash Moonclaw

Roll at the end. Whether you make a skill roll at the end of a one second action or one that takes more time, you won't know if you've succeeded until you finish the whole thing - which generally includes the prep. (Compare to spells with multi-turn casting times.) Optional prep actions, e.g., Symbol Drawing to enhance a subsequent ritual are often made at the end of the prep action since failure simply means no bonus. It would be perfectly legitimate to require simultaneous rolls (with different colored, or otherwise distinct sets of dice) and apply the results of one roll to the other since you might not know how well you prepped until you perform the final action - but these cases are for incorporating variables. (If I required rolls in this fashion I would at least give some chance to "proof" the prep work before the final stage.) Required Prep is generally a Go/No-go determiner. Of course, given the scope of cases in GURPS, subsequent posters may well point out exceptions which I haven't thought of in answering you. When in doubt, I suggest use the above as a default and consider merits of specific cases as they arise.

Thanks. That makes sense. Obviously that makes Preparation Required a more brutal limitation for abilities that require an activation roll vs those that don't.

I wonder, how would you price it if you rolled before the prep time (thus only having to spend the prep time when you know for sure you'll be successful if only your prep isn't disturbed)?

[Snargash Moonclaw]

Of course I'm approaching the matter in the most general fashion below and specific cases might warrant a different response. What ability(ies) prompted your question in the first place? Are you wondering how to adjudicate them (as GM) or play them, or just trying to get a handle on how GURPS works with an eye toward doing either or both in the future?

Originally Posted by JCurwen3

Thanks. That makes sense. Obviously that makes Preparation Required a more brutal limitation for abilities that require an activation roll vs those that don't.

I wonder, how would you price it if you rolled before the prep time (thus only having to spend the prep time when you know for sure you'll be successful if only your prep isn't disturbed)?

I probably wouldn't - the basic truism "You never know until you try," applies. Being certain of success in advance mechanically eliminates the possibility of the sheer bad-luck of automatic failure - I would push that into play (rather than character gen/advancement mechanics) as a matter of "How does the character make this fool-proof?" For play purposes there may be times in which a GM permits an out-of-sequence roll in order to smooth game-flow, but that still implies the possible necessity of having to ret-con the result description if it is in significant conflict with subsequent developments which precede the result in-sequence. Rolling before the prep time essentially results in the character knowing the future, begging the question of how s/he manages to do so.

[jeff_wilson]

Originally Posted by JCurwen3

Thanks. That makes sense. Obviously that makes Preparation Required a more brutal limitation for abilities that require an activation roll vs those that don't.

I wonder, how would you price it if you rolled before the prep time (thus only having to spend the prep time when you know for sure you'll be successful if only your prep isn't disturbed)?

In this case, you could immediately re-try on a failed roll, so depending on the activation roll, it would only add a few seconds to a few minutes of rolling to the front of the preparation time on average; base the limitation on this new, greater total length of time.

[roguebfl]

Originally Posted by JCurwen3

Thanks. That makes sense. Obviously that makes Preparation Required a more brutal limitation for abilities that require an activation roll vs those that don't.

I wonder, how would you price it if you rolled before the prep time (thus only having to spend the prep time when you know for sure you'll be successful if only your prep isn't disturbed)?

That not Preparation Required, that's more along the lines of Takes Extra Time.

[cmdicely]

Originally Posted by roguebfl

That not Preparation Required, that's more along the lines of Takes Extra Time.

Takes Extra Time is also roll-after, and gives more points back than Preparation Required (in part because the time scaling is different, in part because there's no break between the preparation and the use.)

In either case, roll-before is a problem (aside from figuring the cost) for many powers because you may not know the situational modifiers that will apply at the time of use at the time you begin the preliminary concentration or preparation. (Particularly with Preparation Required, which may be done long before the effect is used.)

What is roll-before supposed to represent? How do you know how well what you are attempting is going to work before you start?