Question on saves and Spike Stones

[FelixA]

The rules read,

Spike stones impede progress through an area and deal damage. Any creature moving on foot into or through the spell’s area moves at half speed. In addition, each creature moving through the area takes 1d8 points of piercing damage for each 5 feet of movement through the spiked area.

Any creature that takes damage from this spell must also succeed on a Reflex save to avoid injuries to its feet and legs.

I'm seeing some folks argue that the Reflex save is made one for the move through the area, while others argue the save is for every 5 foot square. Is there any definitive ruling on this?

[willuwontu]

You don't take 4d8 damage from moving through 4 squares, you take 1d8 4 times for each time you enter a square. Similarly, every time you take damage from the spell (i.e. every 5 ft) you roll a reflex save.

[Mysterious Stranger]

The spell states any creature taking damage from the spell must make a reflex save. It does not say anytime a creature takes damage from the spell. RAW is not clear, personally I would go with a single save per turn spent in the area. Most spells only require a single save, having to make 12 saves seems to be a bit much. Since a 1 always fails that means that someone with a +40 reflex save moving through 60’ would have about a 45% chance of failing his save.

[FelixA]

One for, one against, which is where I was when I began. I wish a developer would chime in. :P

I note under Web, if you're free and moving through a webbed area, you only roll once to see if you're trapped, not every square, so I do see your point in some other spells already.

As you point out, the movement penalty is essentially an auto-fail. If you have a 50% chance of making the save, moving through a single area (20 feet) is a 6.25% chance of making it through without penalty, which seems ridiculous, and the monsters lined up don't have reflex saves even high enough for those odds.

[Mysterious Stranger]

20’ would give you about a 19% chance of failure no matter how high your save. At 30’ it would be about 26%, and at 60’ it would be 46%. Considering the normal chance to fail is 5% that is quite a bit higher. If you fail on more than a natural 1 the chance is even higher. Someone making the save on a 5 or better has an 82% chance of failing if they move 30’. With odds like that why give a save at all? I can see having to make a save each turn that you are affected by the spell.

[Diego Rossi]

I have checked the very similar spike growth, but there is no further information there. It has the same text.

I agree that having to make more than one save in a round for the same effect sounds strange.
On the other hand, failing the save has an immediate effect: "A failed save causes the creature's speed to be reduced to half normal for 24 hours or until the injured creature receives a cure spell (which also restores lost hit points)."
As the creature's speed is immediately reduced we "need" to know when it happened. As soon as it stepped in the area? When it was almost out of it?

Spike growth and Spike stones are clearly patterned around the caltrops, and those say: "Each time a creature moves into an area covered by caltrops (or spends a round fighting while standing in such an area), it runs the risk of stepping on one. Make an attack roll for the caltrops (base attack bonus +0) against the creature.
...
The caltrop deals 1 point of damage, and the creature’s speed is reduced by half because its foot is wounded. This movement penalty lasts for 24 hours, until the creature is successfully treated with a DC 15 Heal check, or until it receives at least 1 point of magical healing."

Note that the spells deal normal damage, probably piercing, as the damage is done by the transformed stone or transformed plants, not by the spell.
Most kinds of DR will heavily mitigate the spell's effects.

All thing considered, I think it is meant to be a save every 5', but after the first attempted save the creature is aware of the obstacle and can try to avoid it. It can't detect the area cowered unless it has Trapfinding, so it is a serious obstacle to non-fliers that do haven't a decent DR.

[Mysterious Stranger]

Diego Rossi wrote:

I have checked the very similar spike growth, but there is no further information there. It has the same text.

I agree that having to make more than one save in a round for the same effect sounds strange.
On the other hand, failing the save has an immediate effect: "A failed save causes the creature's speed to be reduced to half normal for 24 hours or until the injured creature receives a cure spell (which also restores lost hit points)."
As the creature's speed is immediately reduced we "need" to know when it happened. As soon as it stepped in the area? When it was almost out of it?

Spike stones impede progress through an area and deal damage. Any creature moving on foot into or through the spell's area moves at half speed. In addition, each creature moving through the area takes 1d8 points of piercing damage for each 5 feet of movement through the spiked area.

Any creature that takes damage from this spell must also succeed on a Reflex save to avoid injuries to its feet and legs. A failed save causes the creature's speed to be reduced to half normal for 24 hours or until the injured creature receives a cure spell (which also restores lost hit points). Another character can remove the penalty by taking 10 minutes to dress the injuries and succeeding on a Heal check against the spell's save DC.

The description of the spell does not state the creatures speed is immediately reduced after taking damage. The spell actually causes all creatures moving through the area to move at half speed even if they make the save. The saving throw is to avoid long term (24 hours) reduction of speed.

[Diego Rossi]

When you move through an area of Spike stones you move at half speed, the injury halves your speed. They are two different effects and they are cumulative.
When you are injured your base speed changes, 30' becomes 15', 20' becomes 10'. When you move at half speed you move half of your base speed.

[Mysterious Stranger]

There is still nothing in the spell that specifies when the injury occurs other than after taking damage.