Dumbing it down

[Essex]

1) TWK is very powerful
2) Merry's sword is ordinary
3) Merry stabs TWK in the leg
4) TWK falls to his knees and takes no action to stop himself from being stabbed

3 of the above lines are exactly the same as the book. Why can't you take a leap of faith and have the sword as magic? Why couldn't it be the blade of numenour that was given to Merry by Galadriel (which was an obvious play on the blade of westernesse that he gets from Tom)? Just use a bit of lateral thinking and the scene will be OK for you.

If you must see the sword as 'ordinary' then what's that line that Pippin says in the movie that the Mightiest warrior can be felled by one arrow? David slew goliath didn't he? You are viewing things in a very black and white way with no shades of grey. Movie WK is powerful, so therefore can't be hurt by an ordinary sword. Why? Where is this rule written down?

The main premise of the Book (and film) is about the 'weak' defying the odds and saving the day. Why CAN'T the WK be hurt by a blade to his body inflicted by a small, insignificant hobbit?

PS Just HOW do you show cinematically without a narrator that the sword unknit the witch king's spirt/sinews anyway? Who in Middle-earth knew this sword could do this? And we couldn't have gandalf or someone inspect the sword afterwards as it was destroyed in the undoing of the witch king anyway. If a character looked at the blade beforehand and said, wow I bet you could kill the witch king with that magic blade, it would've no doubt given the game away to a few million movie goers.....