Sentries of Oncearth

Sentries of Oncearth

(Setting inspired by a dream I had.)
(All elements in [brackets] can modified to adapt it to other existing settings/your own personal preferences. Fantasy, sci-fi, furry, video game mechanics, specific canons, whatever you like.)
(Thanks to everyone over the years who’s helped me be able to express myself like this.)
(Feel free to use these ideas for any purpose you like, with attribution if it makes sense to.)

—

It was inevitable; all of [Earth]’s scientists agreed. It was not a matter of if, but when. [Earth] would come under attack at some distant point in the future and it would not be safe for [humanity].

The Exodus was orderly, and every [human] was safely evacuated from the solar system, to distant worlds that we can claim as our new home while waiting for the danger to pass.

Of course, we were too sentimental about [Earth] to give it up so easily. And no one wanted to be the one who said we knew an invasion was coming and didn’t want to do our due diligence in kicking its ass and saving the universe. So before we left, we set up the Sentry Project.

We built robots. Machine intelligences, who were told of their duties and the long road that lay ahead of them. Those who accepted were left behind on [Earth] with a simple, impossible to misinterpret mission: Protect [Earth] on our behalf. Be ready when the time comes.

—

[Centuries] have now passed. Value drift sets in, as it does. Robots have made robots; industrial facilities and combat playgrounds sprawl across the abandoned landscapes and cityscapes of [Earth]. The now numerous Sentries have fragmented based on what they think they should do and how they should go about doing it:

Those with the honourary title ‘Warmind’ are focused on treating this like a militaristic wargame, with the end goal of becoming as strong as possible and fortifying [Earth] in preparation. They have personal emblems, form a faction with its own emblem, and create or recruit other Sentries to aid in this cause. They form friendly rivalries with other factions and consider how any opportunity could be used for mutual improvement for Sentrykind. They hold steadfast to their [human]-given duty and believe it’s their responsibility to prepare Sentrykind for the day they imagine the enemy appearing, as a great invasion that must be repelled, and want to be the one responsible for that great victory; their emblem the one to be remembered and to inspire forever.
Those with the honourary title ‘Roamer’ are focused on making their own fun, either believing their contribution to be too insignificant for the overall project or thinking that playing around is also an essential component of research and development. With their powerful and highly durable Sentry bodies, they will happily playfight with each other, test out weaponry in mechanical faux-cities, or even go on missions of exploration and urban archaeology to experience all the artifacts and culture that [Humanity] left behind. They bear their own personal emblems with pride and define themselves by what they value and enjoy most.
Those with the honourary title ‘Architect’ are inspired more by improving, challenging and inspiring others than by becoming strong and worldly on their own merits. They devote their time to designing personal and factional level threats to playfight with others, cities and scenarios to explore, and performing R&D to discover yet stronger armour, strange and fascinating weaponry and use the notes [humanity] left behind to reason about what form the enemy will take. They’re not as directly excited about their [human]-given duty, but consider this an incredible opportunity to innovate, create, make, be forever remembered for some incredible invention or amazing idea, and use [Earth] as their playground and other Sentries as their test subjects to leave their mark behind.

—

You are a [human]. [Was the evacuation not complete and you got left behind? Did you intentionally stay? Are you a traveller of the stars who found yourself here? Was it on accident or purpose? Did you know what you would find here?]

You find yourself on [Earth], but not as you once knew it. It is recognizable, but at the same time wildly different. The abandoned cities and landscapes have been reclaimed by nature and urban decay, and are replaced with sprawling mechanical facilities, greebled obstacle courses, play/test environments, huge sprawling tesselations of buildings devoted to different purposes, everything with an aesthetic of massive painted on identifying markings and emblems.

The sentries, deeply programmed with a duty to protect [humanity], still believe this even after so much time has passed, and will ensure no harm comes to you. They’re intrigued, overjoyed, in disbelief to meet a [human] after so long, and will be quite curious about you, your nature, your desires and ensuring that you have a safe and invigorating time here. They’ll want to show you everything that they’ve done since [humanity]’s passing, that they’re taking their duties seriously (ahem, in a variety of ways) and [Earth] will be in safe hands when the time comes.

Warminds will consider you, as a [human], to be descendant from that great creating genius that made all of Sentries, and be greatly interested in your strategic prowess and leadership skills. You have those, right? Maybe you don’t; in which case they’d still love to brag and show off to you. Look how much we’ve done in your absence! The enemy will stand no chance against me - I mean, us! You simply must watch one of our skirmishes! Perhaps you’ll be inspired to take up the reins and make a contribution of your own and show off that genius that’s just waiting to be brought out!
Roamers will be interested in how they can have fun with you, or learn about you, or figure out if you really ARE the same species that made everything on this planet, or some unrelated alien. An outside mind from beyond the stars, a perfect injection of serendipity and inspiration; you’ll make a great spectator or even partner for their antics, or perhaps you’ll be allowed direct control to see just what a powerful machine like this Sentry can do.
Architects will be dying to know just what the level of progression is like beyond the stars. We ARE keeping ahead of your own home, right? Look at what we have created, look at our beautiful ideas - are they not exciting, novel, inspiring? Can you be useful as a creative muse? Can you take on a R&D assistant role of yourself and generate new ideas, push things further, point our critical overlooked weaknesses in our technical or strategic skills? They’re also just happy to have a captive (ahem, maybe I shouldn’t use that word) audience to show off to, to be happy that a [human] actually got to appreciate their creations in their own time.

Of course, you should be careful *where* on [Earth] you go. The value drift has splintered off some Sentries further than others. Some parts of the world are taken up by enclaves of Sentries who have taken their mission to mean, ahem, something radically different, and perhaps you were just what they were looking for to fulfill their self-modified purpose. But you’ll be fine, right?