system
Given the following post, respond as if you're commenting on Reddit:
human
[General] What prevents ramming in space combat?

Obviously FTL travel would not feature movement in a classical sense but there are many science fiction settings including very fast conventional ship drives.

Even fairly small sized objects moving at relativistic speeds would devastate most targets including planets.

A lot of books and movies featuring widespread space combat won't really go into this issue at all although Star Wars for example has shown it as an effective tactic that for whatever reason has been very much underutilized.

What are some explanations authors or genre enthusiasts have come up with to explain the lack of using collision tactics with spaceships?
gpt
A common explanation are energy shields that prevent relativistic objects from hitting the ship by either repelling it or by distributing the kinetic energy across the whole shield surface.

That's also why these kind of settings feature energy or plasma (ship-) weapons instead of ballistic ones, because these can supposedly break through them or at least make them weaker until they collapse.