Neil Gaiman and Roger Avary, the screenwriters of Beowulf (3-D), certainly understood the plot of the epic Anglo-Saxon poem on which the film is based. They understood that the basic theme was one of heroism, that the poem was a study in character and kingship, that it had possible Christian sub-texts, that the fabled monsters had psychological implications. In making extensive changes to both the plot and themes of the story, they did so in a studied way with the intent of both modernizing the poem and making the story more palatable and interesting to contemporary audiences.

There is no rule against making changes to a story when it is adapted from text to film. Some of the worst adaptations have been faithful to their sources (and some have been equally unfaithful). Film is a commercial medium as well as an artistic one. If you don't sell tickets and attract an audience, you fail, at least by one definition of film.

Beowulf the poem is basically a narrative about an epic hero. The poem lacks much self-consciousness. It's artful, but the artistry to me seems more the result of the story being told and the culture in which it occurs. Beowulf the poem is largely unaware of itself as artifice, as art, and its purpose is the telling of history, the forging of legend to be grafted on to a developing cultural and national consciousness.

Beowulf the film is highly self-conscious. It is torn by a desire to do right by the poem and the desire to be commercial. All the changes made in the conversion of the source text to film appear to have been made with these contending desires in mind. By changing the poem and by failing to provide in the changed narrative a unified logic equally compelling to that in the source, the film falls short.

The film preserves most of the basic events of the original story, although it sometimes reconceives and embellishes them. The three monsters — Grendel, his mother, and the dragon — are all there. Beowulf continues as the hero of the Geats who hears of the monster that is threatening Hrothgar's people and comes to the land of the Geats to vanquish it. He does so because he wants fame and the power that fame brings. This is not so different from the poem. But the film makes Beowulf a flawed hero, and in the poem few if any flaws are evident. Beowulf in the film (played by Ray Winstone) is arrogant and proud, and in his quest for victory he is willing to compromise himself — he lies to Hrothgar about killing Grendel's mother and about losing the treasured golden horn Hrothgar had given him; he does not reveal that he had sex with her.