Jackson has said that he purposefully left Tom Bombadil out of the film because he felt that Tom's meeting with the travelling hobbits did not advance the story, but rather held it up. It is possible to remove Bombadil from the story completely without affecting any later events. Another factor is that after trying very hard to convince the audience that the Ring corrupts everyone and is dangerous, Tom is seen to be apparently immune, reducing the threat of the Ring. However, in a small nod to Tom Bombadil, Treebeard uses Bombadil's incantation to save Merry and Pippin when they become trapped by the roots of an old tree in Fangorn Forest.



It is worth noting, however, that after the Hobbits leave Bombadil's home, they must cross a land of "downs" (grasslands with hills) that are dotted with "Barrows" or underground graves from a much earlier kingdom. Tom warns them away from these structures but they get lost in the fog. He has given them a rhyme to summon them, as if knowing they will get in trouble. A "Barrow-wight", a sort of zombie—neither living nor dead—inside the mound, captures them and is about to kill them when Sam wakes up and attacks it. They recite the rhyme and wake up later (after passing out) on the grass, naked. Tom tells them to "run about" and clear their heads while he searches for things in the barrow, To show how old he really is, he finds a woman's brooch and reminisces, "Fair was she who long ago wore this on her shoulder!", indicating some romantic relationship in the distant past.



But much more important are the Elvish blades he finds and gives to the Hobbits as swords. Merry's proves a lifesaver and a sword that turns the tide of the Battle of the Pelennor, when he attacks the Witch King of Angmar, who has disabled Eowyn. It turns out that his blade has the power to sever the "undead sinews" of the King and banish him from the world of the Living. In the film, it seems to be owyn who does this, since she is "no man", but in the book, it is Merry's blade. Both he and the shieldmaiden are sickened by their contact with the Ringwraith, not as badly as Frodo, but in the book, they are taken to the Houses of Healing inside Minas Tirith and healed by Aragorn. In the movie, they seem to have "double-teamed" him into becoming really dead, instead of just "undead". Edit