Speed reduction effects stacking?

[Malin Genie]

If there are several effects that reduce speed (the particular examples I was thinking of were Spike Stones and Sleet Storm, both of which 'reduce movement by 50%) do they

(a) Not stack at all

(b) Stack multiplicatively (so two effects that halve movement reduce movement to 1/4)

(c) Stack additively (the "3E" way - so halving movement is a 50% reduction, and two 50% reductions is a 50% +50% =100% reduction)

(d) None of the above

 

[Hypersmurf]

You left off one other possible interpretation of the "3E way", which is that you add the denominators using 3E multiplier math.

In other words, half of half is a third, half of a third is a quarter.

-Hyp.

 

[Malin Genie]

I always thought the '3E way' was to convert multipliers into additions - so 2x is +100%, 3x is +200%, 0.5x is -50%. But if you view 1/2 as '+100%, then invert at the end' I suppose you could get (albeit tortuously) to 1/2 '+' 1/2 '=' 1/3....

Is that how you would rule it as a DM, Hypersmurf?

 

[Hypersmurf]

Yeah, I think so.

Spike Stones and Sleet Storm haven't come up in conjunction yet, but if they should both coincide on an Entangle spell on a blinded person, I'd rather see him moving at 20% speed, than moving his normal movement rate (only backwards).

-Hyp.

 

[Antikinesis]

What?! Movement multipliers that stack?! Who ever heard of such a thing!

But if you cast Slow on the party, when they're wearing Boots of Striding and Springing on the wrong feet, while they're entangled, blind, and hiding in a sleet storm...

Nevermind. Nothing good can come of this, I'm sure.

-AK

 

[kengar]

The party I DM just finished a big fight against some pretty tough gnolls on a jagged mountaintop. They (the party) were attacking a fortified position (a ruined tower) uphill through a foot of snow in a blizzard. The modifiers worked out to *1/3 for movement and -4 to ranged attacks for visibility (falling snow). *1/2 for the snow and I Rule Zeroed it to a final result of *1/3; adding in the terrain (rocky, up a relatively steep slope). It could have just as easily been *1/4, but I simply just didn't want the combat to take that long.

 

[melkoriii]

What?! Movement multipliers that stack?! Who ever heard of such a thing!

But if you cast Slow on the party, when they're wearing Boots of Striding and Springing on the wrong feet, while they're entangled, blind, and hiding in a sleet storm...

Nevermind. Nothing good can come of this, I'm sure.

-AK

Dont forget to add in a Tanglefoot bag for another 1/2 movement.

 

[Antikinesis]

It's funny how people are so much more accepting of the stacking of multipliers that halve your movement, than they are of stacking multipliers that double your movement.

(Don't mind me. Just throwing rocks at a beehive.)



-AK

 

[Stalker0]

Dont forget to add in a Tanglefoot bag for another 1/2 movement.

You forgot the mightest of all, slow fog!!

I had a dwarven cleric in full plate in a slow fog. He had to run to move 5 feet

 

[RigaMortus]

Earth's Stagnation is an OA spell that further halves a targets movement =)

Actually, I have a question about this spell. I'll make a new post though as to not hijack this one.