A before/after business rule modifies the same field or related record that triggers the same business rule to execute again, creating an infinite loop. (high likelihood)
Multiple business rules are triggering each other in a circular pattern, where Rule A triggers Rule B, which triggers Rule A again. (high likelihood)
A business rule calls gr.update() or gr.insert() on the current record or a related record that has the same business rule conditions, causing re-execution. (medium likelihood)
A business rule uses setValue() on a field that is also being modified by the same business rule in different execution paths or conditions. (medium likelihood)
Workflow or other automation triggered by the business rule is updating fields that cause the same business rule to fire again. (low likelihood)