ThirdWizard said:
Note that the description says:
Emphasis added.
So it isn't that the character feels attached to it, since the character can want to draw others.
Ergo, the character would feel no qualms about smashing it on the dungeon wall.
Oh, it doesn't change the character's mind or personality.
Okay, I should qualify -- the RAW don't say the sword changes your personality or makes you think the sword is a good weapon when it isn't. It does, however, hijack your body -- and to some degree your mind, since using a sword is a somewhat complex action -- to prevent you from doing what you want.
Picture an Evil Dead scenario where you *try* to break the sword but your hand won't obey your mental commands.
And yes, this does have to be a somewhat sophisticated curse. It's not of the simple, purely physical "My hand won't let go!" variety -- it doesn't just "stick" the sword to your hand, it forces you to *keep the sword in your possession* and forces you to *draw it and fight with it*. In other words, you can't fool the sword by drawing the sword but then using a pistol bow in your off-hand -- you have to *use* the sword. A curse that sophisticated isn't going to let you just take the sword and purposely smash it.
BTW, I just looked it up -- by the RAW, the standard -2 cursed longsword can't be uncursed by _dispel magic_ or _remove curse_, only by _limited wish_ or higher effects. So yeah, it's a pretty darn sophisticated, powerful curse. The sword isn't actually intelligent, and you could consciously "trick" it by, say, asking the rogue to try to disarm or grapple you and then destroy the sword for you, but just smashing it yourself isn't gonna work.
And I should point out, the wording specifically says "The sword can only be gotten rid of by _limited wish_, _wish_, or _miracle_", implying that much simpler, more intuitive ways of "getting rid of it" like smashing it against a rock are specifically intended not to work.