Goofs

The final battle with the dragon takes place during an eclipse and a magically-summoned thunderstorm. When the dragon rises above the cloud cover for its final attack, it's in full sunlight.

It has been stated that "In the dragon's lair, a wizard sees the dragon reflected in the water as it rises up behind him. Only things in front of or above a viewer would be reflected in a flat surface."

However, it has already been shown that Galen has the ability to see visions of events in other locations in the water like a reflection. So he doesn't require a reflection to see the dragon in the water.

When the solar eclipse takes place, the moon slides in front of the sun, from below. In real life, the moon moves from right to left (northern hemisphere) or left to right (southern hemisphere). However, as this may not take place on Earth, the placement/movement of astral bodies could certainly be quite different. Another explanation could be that this is not a natural eclipse. It seems to take a long time to occur, and clears as soon as the dragon is dead, suggesting it as an unnatural occurrence.

When the first girl is chained up for the dragon, she wrenches her hand free from the shackles. The soft padding inside the shackles is visible for a few shots. When the shackles appear later on, they are plain metal.

Obvious matte work during some of the flying sequences and when the dragon is moving on the ground.

In the Paramount Widescreen Collection edition, during the lottery scene the man drawing the tiles reads the name "Princess Elspeth Ophelus; Filia Regis," Latin for "Daughter of the King". The subtitles say "Clearly outrageous".

When the wizard teleports to the mountaintop for the final battle, thunder continually rumbles under a clear sky, even though the wizard hasn't yet magically summoned the electrical storm (which he will do in a few moments).