And Inigo's face began to bleed. Two rivers of blood poured from his forehead to his chin, one crossing each cheek. (5.375)
Yup, this ain't your preschool fairy tale. We're talking serious action with lots of blood. And you'd better get used to it, because there's more where this came from.
"You're killing her!" the Sicilian screamed, showing harder with the knife. A drop of blood appeared now at Buttercup's throat, red against white. (5.834)
One thing that Goldman is very good at is making us wonder what's going to happen next. For example, the general rule in a scene like this is for Buttercup not to get hurt—but now that the Sicilian's knife has broken her skin and made her bleed, we're not really sure anymore what's going to happen next.
He had been bitten, cut, gone without rest, has assaulted the Cliffs of Insanity, had saved and taken lives. (5.1192)
It's fair to say that Westley has been put through the ringer in his quest to get Buttercup back. And along the way, a person or two has had to die.
It would not stop. It simply hung now below the sky, an audible reminder of the existence of agony. (6.218)
When Count Rugen first tests his pain Machine, he tests it on a wild dog, and the animal's scream is so awful that everyone in Florin can hear it. The scream is so bad that you almost feel pain just hearing about hearing it.
Inside and out, Westley's world was ripping apart and he could do nothing but crack along with it. (6.282)
Up until now, Westley has been able to withstand Count Rugen's attempts at torture by taking his mind away from his body. But Count Rugen's pain machine ensures that this is impossible, because it invades every last inch of Westley's body and mind.
[He] began to whip the beast against the walls like a native washerwoman beating a skirt against rocks, and […] the snake was dead. (7.61)
When it comes to killing snakes, Fezzik doesn't leave anything up to chance. A snake has tried to kill him, so he returns the favor by swinging the thing and beating it against a rock until it's dead ten times over.
The Count's frozen face was petrified and ashen and the blood still poured down the parallel cuts. (8.125)
Inigo Montoya shows no mercy when he finally gets his chance to kill the man who murdered his father. And we can't say that Count Rugen deserves a better fate, since he has more or less dedicated his whole life to causing pain to others.
"The first thing you lose will be your feet […] The left, then the right. Below the ankle. You will have stumps available to use within six months." (5.140)
Westley is good at making vivid threats. But then again, he needs to be since he is completely paralyzed at this point and his only chance against Humperdinck is to bluff the guy into giving up without a fight. Luckily for him, it works.
The noble killed him then, with no warning; a flash of the nobleman's sword and Domingo's heart was torn to pieces. (5.352)
His heart was "torn to pieces." Again, Goldman doesn't disappoint when it comes to vividly describing scenes of total violence and pain. It just makes us all the more sympathetic to Inigo's plans to kill Count Rugen.
Then he took the remains of the man in black, snapped him one way, snapped him the other, cracked him with one hand in the neck, with the other at the spine base, locked his legs up, rolled his limp arms around them, and tossed the entire bundle of what had once been human into a nearby crevice. (5.796)
Don't worry, this isn't really happening. It's just what Goldman wants us to think is happening because it builds all kinds of suspense and a total "What the…?" reaction from all of us. Uncertainty is the key to keeping an audience off balance, and Goldman is really good at using violence to create this uncertainty.