[PFS] Physics shenanigans


Advice


So today I wanted to try the ever so interesting "Feather Token: Anchor attached to an Arrow" Trick, giving it some thought about how I'd need to shoot my arrow to get full efficiency. I figured that my GM, if I told them that I was shooting with my feather token arrow and hit, would make up some b%+@&%!# excuse that the arrow isn't sticking into my opponent or something, so I figured I could try to shoot above the opponent and than activate the Token using a verbal command. But than I'm told that my character, a Zen Archer monk with an intelligence of twelve, couldn't time the right moment when my arrow would be above my target and use the word command to activate the feather token. What the f*~#?

So what sort of skill would my archer need in order to logically be able to calculate the timing and angle to shot an arrow above my opponent at the right moment to activate the feather token to turn it into an anchor, which I would hope drop right on top of my enemy?


Lol


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Diplomacy. To convince your GM that it would be fun to do.


What exactly are you trying to do? Anchor a person? Because that only works on a "craft". If you're trying to hit them with it to cause damage then you have to use the falling object rules which are based on the size and distance fallen. Anchors aren't that big, and the farther away you have to aim them from the less chance you have to hit. It's minor damage at best.

That all being said, there's no way for you, by yourself, to do this. Shooting an arrow is an attack. With no listed action anchor tokens default to standard action to use. So unless you have some way to attack as a swift or move or get an extra standard action, you're never using these at the same time.

From previous editions a Wisdom check was used to determine when best to activate something (specifically feather fall and Sharn, city of towers).

If you're trying to use the momentum of the arrow to make the anchor move, that doesn't work (with physics or the game rules). Momentum is mass*velocity and is conserved. If you increase the mass the velocity will drop proportionately. In this case, making your anchor fall to the ground. If you do it after the arrow hits then you've... spawned an anchor next to them. Is there a point to that?

If you want to aim to drop the anchor over them that's at least a valid way to attack (if you can work out the whole two standard action thing). It's either a DC 15 reflex save for half for them (if you target a square) or a ranged touch attack with a range increment of 20 feet. I don't know where you'd start from, presumably your actual square to where the anchor dropped from to the target to find how far away you were "targeting". As a medium object it would do 3d6, half if it fell less than 30 feet and double if it fell more than 150 feet. Really, not worth it.


You might want to look into the spell contingent action. That would allow you to fire the arrow and speak the command word at the same time (also you could use a regular anchor instead of a feather token thanks to shrink item).

The way turns/rounds work, you would not have to worry about timing. The only things that really interrupt the flow of combat on your turn are readied actions, attacks of opportunity, and immediate actions. Otherwise, if it is your turn, nobody else should be moving. Really your only concern should be if the enemy readies an action to move out of the way of falling objects.

Targeting the individual square above them is where I'm coming up short. There are rules for splash weapons targeting squares here, but I cannot find anything for normal arrow attacks.

The best I can find is the Imbue Arrow ability of the arcane archer, but it doesn't fully address attacking vacant squares.

Hopefully somebody else has more information on attacking an empty square?

Liberty's Edge

As far as firing the arrow and speaking the command word with the intention of getting a flying anchor of pummeling, if your GM leverages any knowledge of physics, it will not work. If you try to apply the momentum of a feather to the weight of an anchor, the anchor is just going to drop straight to the floor. However, other less-knowledgeable GMs or those GMs who like the creativity of the idea might let you do it.

The only reasonable (and I use that word a little loosely) way I can see a GM allowing it would be to sink the arrow into a surface above the target and then give the command word. In this situation, it then most resembled a deadfall trap, so I would probably make it an Atk +10 for 3d6 damage if it was 30 feet up (half that if less than 30, as Bob said above).

Just my 2 cents.


Fist2Jaw wrote:

So today I wanted to try the ever so interesting "Feather Token: Anchor attached to an Arrow" Trick, giving it some thought about how I'd need to shoot my arrow to get full efficiency. I figured that my GM, if I told them that I was shooting with my feather token arrow and hit, would make up some b~%+*@+# excuse that the arrow isn't sticking into my opponent or something, so I figured I could try to shoot above the opponent and than activate the Token using a verbal command. But than I'm told that my character, a Zen Archer monk with an intelligence of twelve, couldn't time the right moment when my arrow would be above my target and use the word command to activate the feather token. What the f*+$?

So what sort of skill would my archer need in order to logically be able to calculate the timing and angle to shot an arrow above my opponent at the right moment to activate the feather token to turn it into an anchor, which I would hope drop right on top of my enemy?

Common sense is the skill you are after. Mostly because it is used to understand stuff like this is not a viable tactic and your GM is sensible to shoot it down.

BUT RULE OF COOL!
It is pretty cool, if you pull it off once, I'd definitely allow it (unless it's to one shot a BBG with flimsy rules). Any medium threat? You're on.
I suggest your GM make you take a REFLEX save since it is the closest we have to MADSKILLZOMG in the real world.
Otherwise Profession: Ballistic Engineering, with an Int score to match.


Bob Bob Bob wrote:


If you're trying to use the momentum of the arrow to make the anchor move, that doesn't work (with physics or the game rules). Momentum is mass*velocity and is conserved. If you increase the mass the velocity will drop proportionately. In this case, making your anchor fall to the ground.

Uh I know know momentum is conserved in the real world. Unless there is something in the rules that say momentum is preserved when physically impossible things happen, then it may well not be.

Actually it is at least arguable that when mass magically changes it is velocity that is preserved.
Why? Well when a persons mass changes with with enlarge or shrink person, just take mass halving with shrink person for an example, if momentum is preserved their velocity will double. Which means relative to their immediate environment, they will fly rapidly in the direction a) that Golarion is rotating, b) that Golarion is orbiting and c) that the solar system is in is orbiting the core of the galaxy.
I look forward to further discussion of this issue, which I will dub the "mass debate".
On if the original idea will work, the feather fall doesn't say how it work, just the effect.
But it does say this- " This spell has no special effect on ranged weapons unless they are falling quite a distance. If the spell is cast on a falling item, the object does half normal damage based on its weight, with no bonus for the height of the drop."
Which could possibly be interpreted to mean that the idea does not work. Or not.


new physics question! (sorry to derail but its yhe physics sjenanigans indeed):
Someone atop a mast of a moving ship casts featherfall and lets himself drop. Where does he land? Ship has one mast. Wind speed is considered 0.


At the bottom of the mast - where else?

Sovereign Court

Errant Mercenary wrote:

new physics question! (sorry to derail but its yhe physics sjenanigans indeed):

Someone atop a mast of a moving ship casts featherfall and lets himself drop. Where does he land? Ship has one mast. Wind speed is considered 0.

You said moving ship, and I'm gonna assume crow's nest is 60 feet, and I'm gonna assume the captain is not turning the ship to a new heading. Therefore, he lands somewhere along the sterncastle or in the water in the wake of the ship at a distance from the mast equal to twice the ship's speed. If ship moves at a speed of 30 (min speed as per Player's Guide to Skulls and Shackles), the hapless fool lands at a distance of 60 feet aft of the mast he jumped down from (because in naval combat grid terms, the ship moves at least 30 as a standard, and at least 30 as a move action; even if the Captain fails his sailing check, the ship continues directly forward at its speed, which is a min of 30).

Sovereign Court

For crow's nest of other heights, the formula is:

Distance feather falling character from aft base of mast when he lands on deck/water = Ship's_Speed*Crow's_Nest_Height/30


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You do realise the falling person has the same inertia as the velocity of the ship, right? So in effect, he's falling forwards as seen from a stationary point outside the ship. And thus lands straight down as seen from the ship itself.

You don't get hurled backwards when jumping up in the subway either. (Good thing, that.)

Sovereign Court

That would be right if you fell normally, via gravity. However Feather Fall says you fall *slow*, and thus I'm of the opinion you're like a feather that you would release from the crow's nest i.e. subject to a relative wind speed equal to the ship's speed... Skulls and Shackles Player's Guide further adds that someone under gaseous form does *not* move with the ship, so in the absence of specific rule for Feather Fall I am going with that.


Ya the feather fall caused the person to land behind the mast because, even though zero wind, the ship wasn't specified to be in a vacuum, so the aerodynamic forces should affect it to move both relative to the sea floor and the ship instead if just one). So both are half right/wrong


OK, in the same example what happens if the person casts enlarge person on themselves when half way down?

Grand Lodge

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Trying to rationalize physics to a game world where combat is turn based and magic exists is how you end up with stuff like the peasant railgun.


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This way lies madness.

Once you get thermodynamics and relativity involved with polymorph, nothing good will result.

There's a reason that science and magic are different things.


So nobody has any information on the rules around attacking an empty square? That would be the final piece we need to support the situation presented by Fist2Jaw under RAW.

Grand Lodge

Purple Dragon Knight wrote:
That would be right if you fell normally, via gravity. However Feather Fall says you fall *slow*, and thus I'm of the opinion you're like a feather that you would release from the crow's nest i.e. subject to a relative wind speed equal to the ship's speed... Skulls and Shackles Player's Guide further adds that someone under gaseous form does *not* move with the ship, so in the absence of specific rule for Feather Fall I am going with that.

If Feather Fall cancelled forward inertia, even worse things would happen. Using Earth as an example, if you jump off a tower and cast FF, you would be smacked by the tower that's spinning at earths speed ever eastward (roughly 1K MPH near equator).

Maybe they should just fall to the bottom of the mast...

Grand Lodge

Pink Dragon said it best, but I'm unsure how you could activate an item no longer in your possession.

Handing it to the wizards familiar on the other hand...

Dropping an object on a creature requires a ranged touch attack. Such attacks generally have a range increment of 20 feet. If an object falls on a creature (instead of being thrown), that creature can make a DC 15 Reflex save to halve the damage if he is aware of the object. Falling objects that are part of a trap use the trap rules instead of these general guidelines.

Also, it the GM has issue with the timing, you could always shoot the wall above the target, and then say the command word (requires contingent action as Spaceball specified above or another standard to activate).

Make it cool, instead of cheesy and most GM's will allow it as a one-off.


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Command Word items take a standard action to activate so you cant combine using it with shooting it at someone.

Sovereign Court

My previous example failed to account for the presence of the third mast. So use my formula for single mast vessels.

In the case of a three mast sailing ship the answer would be: after jumping from crows nest the sails and rigging of the third mast catch you. You are now entangled approximately 30 feet above the sterncastle (climb checks required to move down safety; DC 20)


For all of these questions you need to know the frame the magic locks to.

Even if enlarge or reduce person does conserve momentum it not unreasonable for the spell to also assume the world is not moving. This is quite useful for many rule cool situations that try and take advantage of it.

As for feather fall, if he falls 60 feet or less then he is at the bottom of the mast. If it is more then that then the boat gets a turn and can sail out from under him. Falling happens on the turn you fall and is also completed then unless it is more then 500 (or 60 with FF) in the same turn. This makes no sense with physics but makes game play simpler.

It would not be at all far fetched to thing that the spell anchors the ship and you end up at the bottom of the mast even on 200 foot fall with starts and stops by the boat. Since flying creatures do not anchor to ship then I do not think that FF does either.

What if the ship is an animated object and has life bubble cast on it?


Mathius wrote:
Even if enlarge or reduce person does conserve momentum it not unreasonable for the spell to also assume the world is not moving.

Well, the spell would be wrong, as Golarion exists in a solar system.

Magic can't really happen. But if you have spells that do things like suddenly change mass, you can deduce that conservation of momentum is wrong in the PF universe. The reasons are in my first post.


There is no reason to conclude that Conservation of momentum is not true in Golarion based on your examples.
All of your ways to breaking it use magic, we know that magic taps an energy source so that it can generate fireballs etc. So when you change the mass of an object with magic you are also messing with energy , if you expend work on an object then momentum is not conserved as you have added energy to the system.
So you object which doubles in mass continues to move at the same velocity but now has twice the momentum and Kinetic energy due to the magical influx of energy. When you halve an objects mass likewise it continues to move at the same velocity and has half the momentum and KE the surplus energy being siphoned off to the realm of magic .

Conservation of momentum and Thermodynamics work in closed systems when you use energy to do work on the objects from outside the system then there is no conservation of energy. If you expand your model to include energy sources form magic it is still probably conserved.

(Of course the existence of extra planes and magic does imply that current physics models are not complete for the Golarion universe , then again we know they are not complete for the real world, so momentum may not be conserved in Golarion)

Also assuming the world is not moving is a perfectly valid for physics , if we define of plane of reference such that Golarion is not moving we just have to factor that into the movement of other bodies as they are outside the context of the experiment that is not a problem. This is one of the things you have to do to be able to handle relativity anyway.

My physics degree is a long time ago or I may have been able to do some of the math needed


JohnHawkins- An intelligent post I don't fully agree with.

In the real world, the law of [Newtonian} physics is- Momentum = mass X velocity.

I said if you magically change mass, this does not apply and you have to preserve either velocity or momentum, and to make sense of the world you have to preserve velocity. [Technically, neither mass or velocity could be preserved, but lets leave that aside].

You said that if you magically change mass, you need to preserve velocity to make sense of the world you have to preserve velocity. You say that you introduce an adjustment into the equation to make it balance when magic is involved.

So the same thing happens we just describe it differently. Whose description is more useful? I suggest mine. Reason being, once magic gets involved, you can't use the real world calculation Momentum = mass X velocity.

With your description, you say Momentum = mass X velocity, but you introduce an adjustment for magic into the calculation.

Say- Momentum = mass X velocity X Magical Adjustment. And to use your equation, you need to deduce what the Magical Adjustment is from the real world equation, then introduce it into the Golarion equation to make it balance.

I am afraid I may not be being clear.


*continues fishing with bait from [Opened Can Of Worms]*

It is a fun discussion :) though I think it all hinges on 1. what physic rules are obeyed/obviated and 2. Do turns/initiative affect these set rules in play.

Because you can put all the rules you want but if the ship is having its turn while you fall, it is going to get weird.

We ruled it as falling by the mast, by conserving inertia and ignoring air pressure/resistance (to not discuss whether your mass is the same or that of a feather falling). If wind effects are severe, they will factor in.

My players laughed at me when I was about to say he'd fall in the water..."physics doesnt work that way", and i did agree with them. Then I killed one of their characters. Unrelated...of course.


Errant Mercenary wrote:

*continues fishing with bait from [Opened Can Of Worms]*

It is a fun discussion :) though I think it all hinges on 1. what physic rules are obeyed/obviated and 2. Do turns/initiative affect these set rules in play.

You are an extremely naughty man.

The rules of physics work in Golarion just as they do in the real world. Except when they don't, which is mostly when magic or fantastic creatures are involved. Though initiative and turns are not kind to the immutable laws of the universe either, as you say.

From my first post "... when a persons mass changes with with enlarge or shrink person, just take mass halving with shrink person for an example, if momentum is preserved their velocity will double. Which means relative to their immediate environment, they will fly rapidly in the direction a) that Golarion is rotating, b) that Golarion is orbiting and c) that the solar system is in is orbiting the core of the galaxy.
I look forward to further discussion of this issue, which I will dub the "mass debate"."

Which is just scratching the surface of what happens when the laws of physics get turned on and off like a light switch. Or someone is fool enough to try to think it through in detail. :(


You can't hit a gray area of the rules and then try to hit the dm over the head with what the rule is.

Tricks like this are one thing in a home game where you can work out some reasonable compromise between raw, rai, and that newton fellow once and go from there, but in PFS you'll be forcing the issue in combat, on a time limit, repeatedly, and thats not fun for anyone.


Why would you say the command word at the top of the mast? It's not a parachute that needs time to slow you down. It's magic. Just say it at the bottom of the fall, a few feet above the deck - there are no rules about when in your turn you activate this instant ability.


DM_Blake wrote:

Why would you say the command word at the top of the mast? It's not a parachute that needs time to slow you down. It's magic. Just say it at the bottom of the fall, a few feet above the deck - there are no rules about when in your turn you activate this instant ability.

WIN.

It made me scratch my head for a while though, so much to consider!


An object at rest tends to stay at rest and an object in motion tends to stay in motion UNLESS ACTED UPON BY AN OUTSIDE FORCE.

Magic is an outside force.

When A person is enlarged, the magic adds to his momentum and energy, and the magic in the universe is slighty decreased.

When a person is reduced, the magic in the universe takes some of his energy and momentum, and the magic in the universe is slighty increased.

That is why there are two competing secret societies of mages. Society 1 wants to drain all magic from the universe by enlarging everything until all of the magic goes into physical energy and momentum. Their success would turn Golarion into Earth as this is what happened on Earth Centruies ago.

Society 2 on the other hand wants to turn everything into magical energy by reducing the mass of the universe to 0. (Fortuantely lorentz contraction makes this harder than they realize)

As long as these two societies are in conflict the world is safe, but if eihter one ever wins, Golarian as we know it will cease to exist.


There's absolutely no reason to think that feather fall affects horizontal momentum or motion at all. It only discusses affecting your vertical motion. So the guy jumping from a crow's nest and activating feather fall lands on the deck unless something happens, such as the ship turning abruptly, or a gust of wind blowing him away.

Scarab Sages

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Scythia wrote:

This way lies madness.

Once you get thermodynamics and relativity involved with polymorph, nothing good will result.

There's a reason that science and magic are different things.

This reminds me of a question a 6-8 year old girl asked Rene Auberjonois at a DS9 panel at a con I was attending:

Little girl: When you changed forms, did you mass stay the the same when you were little or big?

Rene Auberjonois: Stunned silence for a few seconds You realize I am an actor? I don't actually change shape. When they have Odo turn into a dog, I just don't come into work that day.


Your arrows are moving, on average, at a couple hundred feet per second (ballpark). Your timing window to activate that token is going to have to be millisecond precise to have a decent chance of pulling this trick off. If I was the DM, I'd certainly let you try, but you might get frustrated after a while when you *just keep missing* with that anchor (and blowing 50 gp each attempt). You're going to be bankrupt before you fluke into a hit, in all likelihood.

Y'know - it just seems odd to me that the OP - a Zen Archer - is faffing about with this questionable tactic when the best possible thing he could be doing in combat is what a Zen Archer does best...

Turning targets into pin cushions WITH ARROWS.

Dark Archive

Pathfinder Adventure Path Subscriber

Feather fall + mast argument:

Let's do a different thought experiment. Ezren has been fleeing a horde of orcs, and the chase has led them to the top of a cliff. He smirks, as he has feather fall prepared. He casts the spell and jumps off, shouting an Orcish taunt at the greenskins above him.

Where does he land? The obvious answer is "at the bottom of the cliff," and I'd agree with you there. However, why not "at the bottom of the cliff, assuming Golarion's rotation doesn't smash him against the cliff wall?" Well, clearly, magical falling doesn't stop forward momentum, because otherwise there'd be a lot of unnecessary calculations. Since the spell only cares about direction along the up-down axis and neither of the other two, I'd say that Ezren leaping off a boat travelling at 30'/round down the Yondabakari River would end up at the bottom of the mast in whatever square adjacent to the mast the DM and PC can agree upon.


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We now have both a mast debate and a mass debate. This could lead to confusion.


So the timing window is directly related to the angle of attack, if you shoot an arrow at a much steeper angle you'll have a longer window to trigger it. There's even a feat for doing this (Lob Shot), specifically for shooting over cover. It increases the range increment by one, which seems reasonable for aiming a higher shot (or at least getting a larger timing window). Still doesn't address the issue of what to roll for the timing window.

A better suggestion earlier in this thread was shooting an arrow into the ceiling and triggering the anchor later to drop it on the square underneath it. Still a problem for what skill to use to tell exactly which square is directly above the target (perception?) but the rest should be easier. The AC of a 5x5 square should be 5 (10+(-5)Dex+0size). You'll need to overcome hardness to stick the arrow in. And the final attack would fall under the DC 15 reflex save for half rules because it's not an aimed attack, it's just a dropped object.


Bob Bob Bob wrote:

So the timing window is directly related to the angle of attack, if you shoot an arrow at a much steeper angle you'll have a longer window to trigger it. There's even a feat for doing this (Lob Shot), specifically for shooting over cover. It increases the range increment by one, which seems reasonable for aiming a higher shot (or at least getting a larger timing window). Still doesn't address the issue of what to roll for the timing window.

A better suggestion earlier in this thread was shooting an arrow into the ceiling and triggering the anchor later to drop it on the square underneath it. Still a problem for what skill to use to tell exactly which square is directly above the target (perception?) but the rest should be easier. The AC of a 5x5 square should be 5 (10+(-5)Dex+0size). You'll need to overcome hardness to stick the arrow in. And the final attack would fall under the DC 15 reflex save for half rules because it's not an aimed attack, it's just a dropped object.

As you mentioned earlier - we have timing issues because of HOW a feather token is activated (standard action).

What I'm also trying to get my head around with this odd tactic with an anchor is how you are activating a Wondrous Item when it is not in your possession?

As per d20pfsrd.com:

Wondrous items are usually use-activated or activated by a command word, but details vary from item to item.

Command Word: If the activation is on command or if no activation method is suggested either in the magic item description or by the nature of the item, assume that a command word is needed to activate it. Command word activation means that a character speaks the word and the item activates. No other special knowledge is needed.

(My note: Feather tokens - no activation method suggested, we can reasonably assume a verbal command word activation.)

A command word can be a real word, but when this is the case, the *** holder of the item runs *** the risk of activating the item accidentally by speaking the word in normal conversation. More often, the command word is some nonsensical word, or a word or phrase from an ancient language. Activating a command word magic item is a standard action and does not provoke attacks of opportunity.

(My note: seems like reading the above you should be HOLDING a token in order to activate it - so, once it's stuck in a roof, flying through the air on an arrow, etc - it's no longer in your possession/and you aren't the holder of the item - it becomes, in effect, an unattended object).

So, we have issues of physics, timing and even if possible to activate when the object is not in your possession. Seems like a no-brainer that this tactic isn't going to work.

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