What term describes unintentional or incidental injury or damage to non-target objects or persons?

The term that describes unintentional or incidental injury or damage to non-target objects or persons is "collateral damage." This term is commonly used in military operations to refer to the unintended consequences that occur during combat, often as a result of strikes on legitimate military targets. The focus on collateral damage highlights the importance of minimizing harm to civilians and non-military infrastructure while achieving military objectives. In modern warfare, understanding and addressing collateral damage is critical for maintaining ethical standards and public support, as it can have lasting impacts on the civilian population and the legitimacy of military operations.

Fratricide, on the other hand, specifically refers to the accidental killing or wounding of one's own forces. Error probability relates to the likelihood of making mistakes during operations, and retrograde typically refers to a military movement backward or withdrawal from an area. Each of these terms has a distinct meaning that does not encompass the broader concept of unintentional injury to non-target entities, which is why they do not fit the definition provided in the question.