Well, if a player managed to think up something as deviously creative as shrinking a rope to kill someone, I'd probably allow it, but I'd also make a roll or two to determine whether the rope actually killed the person or just broke as it shrank.
NOTE: According to the spell description, anything being changed that was on a character [within the aura of a leveled creature] would get a resistance check based on the character's applicable resistance skill.
About the barrel of water...I enjoy toying with my characters, so I'd probably have the water come exploding out of the barrel as it shrank. Actually, once the barrel breaks, it's not technically a single object any more, is it? I might actually have it stop shrinking once it exerts its maximum pressure on the water, or just have it stop shrinking once it bursts. Still, a barrel filled with water, in my opinion, is a separate object from the water contained within the barrel.
I think this is an amusing statement after you ridiculed my question asking at what level the effect occurred.
NOTE: I wasn't actually offended.
The barrel of water question was somewhat of a throwaway just to test definition of "object" for purposes of the spell. For me, the answer is pretty clear - the water is not an independent object. The Growth spell on a person seems perfectly capable of increasing or shrinking (when the effect ends) the water, sinew, what have you, inside a person. The water's "shape" is entirely dependent on the barrel and is directly tied to the barrel's existence and so it's certainly reasonable to rule that the water is not an independent object and hence cannot be "left out".
If the wizard deliberately targets the barrel without targeting the water (a slightly plausible request), we have to consider HOW the barrel grows or shrinks.
I specifically asked the question about structural integrity for EXACTLY this type of situation. Nicholas in answering the question said, "Immediate application of the magic makes it work rule." So BY DEFINITION, the object being enlarged or shrunk MUST maintain structural integrity after the spell effect is resolved. Which was the answer I wanted and happily received.
So let's think about that. Except where noted, all HARP spells have instantaneous effect. Let's say I grow a small block of wood with dimensions 10cm x 20cm x 60cm, sitting on the ground by 400 times. After growth, my block of wood is now 40m x 80m x 240m - a rather large block of wood. Does this block of giant wood with a volume of 768,000m
3 displace 384,000m
3 of soil because it expanded it ALL directions instantly? The instantaneous effect and structural integrity aspect would seem to mandate the block of wood remains on top of the ground. By definition, enlargement has to "shove" things out of the way (most notably air). It would seem that IF the enlargement had to displace anything that couldn't be reasonably "shoved" out of the way quickly and without serious damage, then the spell would simply have to fail.
This would apply to shrinkage as well. The shrinkage is instantaneous, so the shrunk object cannot end up where it would have to displace something substantial. So a rope bound around a person shrunk 40 times couldn't break or squeeze or displace the insides of a person and so fails (or alternatively ends up 'outside' the person which turns the spell from a killer into a handy escape spell).
So, what happens if the barrel is shrunk independent of water? If it was air, the barrel would just end up smaller - no questions asked. Since water in this instance is just like the air, we just end up with a smaller barrel of water and a big splash.
Robin