“It is possible to commit no mistakes and still lose. That is not a weakness. That is life.” –Jean-Luc Picard
The laws of electromagnetism could have been incredibly different. Our Universe has two types of electric charge (positive and negative) and could have had two types of magnetic pole (north and south), but only the electric charges exist in our Universe. At a fundamental level, between electricity and magnetism, nature is not symmetric.
But it could have been! Magnetic charges could move and make currents; a changing electric field could induce them; north and south poles could be separated an infinite distance. Magnetic charge could even have been a fundamental property of black holes. In 1982, Blas Cabrera announced the first detection of a long-sought-after magnetic monopole event, and the physics world went crazy.