The premise of No Man’s Sky revolves around the astronomical scope of its universe. It is a procedural generated cosmos with an inconceivable 18 quintillion (1.8×1019) planets that each possess their own lifeforms, landscapes, resources, and climates.
As a nameless planetary explorer you begin to chart the unknown without any clear directive or purpose beyond reaching the center of the universe by 
continually improving your technology to dive further and further into the blackened universe. The mind-boggling part of this is that anything you can see you can reach and investigate. A monolithic mountain range on the horizon, a twinkling star light 
years away, even if you were to point to a random target on the map of all existence – you can go there. Not only that but it is a seamless launch out into space with no loading screen in between. Where you go, how fast you travel, and what you do when you get there is entirely up to you.
Anything you find, wherever you go, you can name it and catalog it for all players to access in a collective database or perhaps they will unexpectedly witness your findings for themselves if they were to ever find your planet.
A 90-10 rule is used for populating the planets with life thriving characteristics and thus forms of life. This ensures that 90% 
of planets will be uninhabitable and 10% will have an abundance of natural elements to facilitate life. Although, even on those planets with the capacity for complex wildlife many will have dimwitted, primitive creatures and seldom intelligent aliens in order to develop a feeling of wonder when you stumble upon something extraordinary.
If you are fortuitous even to come across a thoughtful, intelligent creature – it is an opportunity to form a relationship that can be both profitable in trade and didactic in learning their language and more about the universe. Trading with NPCs will get you new components for your ship, suits, necessary resources (fuel, minerals), and technology of all kinds to help you survive the threats that loom beyond the frontier.
As you explore this universe, the circle of life and randomness of events are no less evident and you will need to prepare for 
everything and anything. Each galaxy, planet, ocean and cave holds a combative force of some kind, and you are at its mercy. Your vessel and space suit are vulnerable in every interaction from dogfights in space to the harsh environment of a blizzard ridden planet. Regardless of the dangers you need resources to subsist and thrive. You’ll collect different resources with your up-gradable laser tool/weapon. Each time you harvest a resource it is broken down into its elements, which are then combined in various ways to develop new technology.
You much be weary of being too destructive and greedy in your pursuit of progress as there are robotic guardians called Sentinels that roam many planets. They track violent and disruptive behavior – responding accordingly to protect the planet and its denizens. The more damage you cause the higher your wanted level and the greater resistance you will encounter.