Haven Worlds are planets that are extraordinarily coddling towards life. Cogniscent species coming from planets like these are remarkably fragile and unprepared for the rigorss of unexpected things... like humans
The higher the number, the more amenable a Haven World is
Class 1 Edit
Slightly less hazards than what is considered normal or average for a cogniscent species to evolve. May contain inconvenient geography and the occasional mildly toxic thing. Few carnivorous enzymes.
Class 2 Edit
A very mild definition of 'challenging'. Life on these planets had it really easy, but they still had to solve a few problems, here and there.
Class 3 Edit
Problems are rare and stuff is bountiful. Inventions happen through boredom rather than necessity.
Class 4 Edit
Everything is easy and nothing hurts. The food animals may put up a bit of a fight, but it ends up looking really pathetic.
Class 5 Edit
The next best thing to paradise. Temperate weather, warm rain, beautiful balmy days and an abundance of tasty and edible things. Nothing is toxic.
Class 6 Edit
Theoretical only. Everything is soft. Even the rocks. There is nothing sharp. All the plants are good for you and taste like your favourite food. All the animals are tame or resemble Al Capp's "Schmoo". Food practically throws itself in your mouth.