system
Given the following post, respond as if you're commenting on Reddit:
human
[Lord of the Rings] Why don't the Orcs stab the horses that Aragorn and Theoden King were riding when they were leaving the castle at the end of the Battle of Helms Deep?
gpt
At first, because they were moving. A moving horseman is a terrifying thing - even when going slowly, the weight of horse and rider give it massive inertia; impact with any part of them can cause injury even before you factor in the blades the riders were carrying.

(One of those things that Hollywood frequently gets wrong: The whole point of fighting from horseback was constant movement. A moving horse adds immense power to your attacks; a stationary horse just makes you a bigger target)

Once they were brought to a standstill, they should have been dead in minutes or seconds - but the uruk-hai held back, either out of a desire to draw out the joy of slaughter that little bit longer, or out of fear of the extremely lethal warriors on the horses' backs. Sure, the second orc to charge would be able to hamstring the horse and drag down the rider, but the *first* orc to attack would get a sword through his skull.