So tonight in our campaign a party member took nearly 80% of damage of his total from a Clay Golem.
The party was mostly 9th level (8 people) and when we were done and went to heal we looked at the full explanation of the ability and were stunned.
No naturally healing. Magical healing needed a DC 26 Caster Level check to succeed.
After much rule mongering we came to this realization. Supernatural healing would automatically fail (cannot make a spellcaster level check on it) and Spell and Spell like would fail 85% of the time due to the constraints on it.
Supernatural - Since a SU affect cannot be dispelled but was technically still magic as per the rules of Anti-Magic, we decide that SU healing could not overcome this ability. (The Golem ability reads "No Magical Healing without Caster Level Check" Anti-Magic states "Supernatural Abilities do not work" therefore Supernatural is Magical)
Extraordinary - This would fall under the realm of Natural Healing and therefore be irrelevant. (Clay Golems are Trolls worst nightmare)
Spell and Spell Like - For a level 9 caster, a flat 85% failure rate. Nothing in the rules to boost it.
Now the question of the night... Why the hell is this ability on a CR 10 mob?
This ability is disgusting and does not seem to fit any of the normal rules. If it is a curse, why isn't it disspellable? If the CL to create a golem was 11 why is it at 26 instead of 21 (I find DC 15+CL difficult creation rules irrelevant to what the DCs against its abilities are).
Did we work around it? Yes. Was the work around sound? ZNo, the DM had to make an on the spot ruling to make sure the game continued (We had our Wizard with Break Enchantment roll to remove the 'curse' and he only did so with the help of Luck domain Cleric giving a re-roll).
Why am I posting this if we worked around it? Because -
A - If somebody is seeing something we didn't I would love to hear it.
B - If not, this thing needs errata badly. (i.e. DC 21 Caster Level, Saving Throw or allowing Remove Curse, Break Enchantment to work on it.)
We were fortunate that we were playing a city campaign with a larger time/resource pool (and a DM who saw the predicament this ability but him in) but if this had happened in a dungeon it would be a game killer as it would leave a party no recourse but to retreat and spend several days expending heals hoping to roll extremely well so they can get back to adventuring.