In this context, “random” means the trigger is something that occurs naturally, but seems spontaneous and unpredictable. The human interpreter has to wait for it to happen and then deliver the message or meaning that the action conveys.

Let’s dive into all the examples I could find:

Aeromancy

Where: Babylonia

What: Interpreting weather to determine the future (or current events). This includes austromancy (wind divination), ceraunoscopy (thunder and lightning), chaomancy (aerial visions), meteormancy (shooting stars), and nephomancy (cloud formations).

When: It’s alluded to in the Bible and recorded by Damascius in the 5th century CE, but likely predates all that.

Fun Fact: The Wisdoms of the Two Rivers practiced austromancy in Robert Jordan’s Wheel of Time series.

Bird Augury

Where: Roman Empire

What: Also known as alectryomancy, an augur interprets the behavior of specific birds to predict whether or not a future endeavor was aligned with the will of the gods. This included flight patterns, noises made, and whether they ate when offered food.

You could only take auspices at night, and the results were only valid for the next day. I can’t tell if that rule was a great racket by the augurs, or the Senate’s great way of never having to commit to a decision.

When: Surviving evidence dates back to 600 BCE, and it was practiced until 100 CE or so.

Fun Fact: The founding myth of Rome involves Romulus and Remus performing bird augury to decide that Rome should be built on the Palatine Hill. Also, until 300 BCE, only members of the patrician ruling class could be augurs. That’s right, powerful, wealthy men gatekept all the various paths to power. Shocking, I know.

Comets

Where: Across planet Earth

What: Observing a comet in the night sky was taken as an omen of a major event. Prior to Newton’s theory of gravity (1687), comets were thought to be signs from the gods. It was Halley who proposed they follow a recurring schedule, the smartypants.

So we know now it’s non-random, but when this practice occurred, it was considered random.

When: Probably forever, but we have written examples from 44 BCE (signifying Julius Ceaser had ascended to godhood after death), 12 BCE (the “star of Bethlehem” announcing Jesus Christ’s birth), and 1066 CE (a good omen for William the Conqueror and the Norman conquest of England at the Battle of Hastings).

Fun Fact: Most of the recorded instances of comet sightings have been attributed to Halley’s Comet (which “returns” every 75 years). The last sighting was in 1986, which coincided with:

• The meltdown of Chernobyl
• The Challenger explosion
• The El Salvador earthquake
• Reagan and Gorbachev started talks about eliminating nuclear weapons
• The release of Top Gun and the NES
• The first observance of MLK, Jr. Day
• My 5th birthday

The next one will be in July 2061.

Want another fun fact? Ancient Aztecs recorded an omen of a fiery comet (the bird with a mirror on its head)…and that correlated with the arrival of Europeans in 1519. Mind. Blown.

Tyromancy

Where: Ancient Greece, the Roman Empire

What: Interpreting cheese. Specifically looking at shapes and symbols in the ridges, holes, crystallization, and rind. And then eating the cheese afterward, naturally.

When: Written accounts of it date from 100 AD, with it reaching the height of popularity in the Middle Ages.

Fun Fact: C’mon, this method of divination is itself a fun fact!

OK, fine, here’s one: Despite recording its earliest mention, Artemidorus considered cheese divination unreliable and grouped tyromancers with “false diviners.”

I also feel like you could combine oinomancy and tyromancy and have charcutomancy (great at parties).