For all Decks:
The main suit of each card defines it, or is what you notice first, while the numbers represent how strong it is.
Hearts Represents Desires:
Maybe they want to travel the universe or rid the galaxy of aliens.
Spades are Physical Descriptions:
They be very small or bright green and cybernetically enhanced
Diamonds Mean Professions:
Spaceship Captain or Interstellar Lawyer would go here.
Clubs are Connections:
Politicians or teachers are people who know people.
The Secret: Every card has a twist. A hidden mutation or a shady past with space pirates might go here. And it can modify the others.
Spades Mean Physical Features
If it is decorated with star charts or really noisy it will say here.
Clubs Represent Dangers
From robust safety measures to death by exposure to vacuum.
Diamonds are Resources
The value within may be gold and jewels, or hidden knowledge.
Hearts Show Inhabitants
You could find the medical officer or a smuggler with a heart of gold.
The Secret: Every card has a twist. An alien hunter lurking in the shadows or impending staff walkout. And it can modify the others.
Clubs Show Politics
A weak leader clinging to power or the beating heart of a star empire.
Hearts are Inhabitants
Scientists studying local plants or a teeming metropolis of billions.
Spades Represent Environments
There could be methane snow, or fourteen moons and two suns.
Diamonds Show Resources
Rare chemical isotopes or star ship building yards are found here.
The Secret: Every card has a twist. Hallucinogenic plants or long lost alien cities can appear unexpectedly. And it can modify the others.