The First Age setting is centered on what's known as the Pan-Terranic Wars. Technically, there was a long period leading up to the wars that is considered First Age chronologically, but setting information will be principally centered on this era. Note: if the name didn't give it away, the Terra setting is a modified version of Earth, presumably at some unspecified point in our future. It contains various modifications to the landscape (due to wars either in First Age or Zero Age), and none of the familiar faces are around, but the names and places can be kept.
The Pan-Terranic Wars were kicked off by Domino Effect; he provided power, in the form of holographic tokens, to anyone in the world, at random. Because these often ended up in the hands of the destitute, the desperate, and the criminal, there was once again a struggle for power; government forces the world over were no longer the top of the food chain. Terrorists, anarchists, and legitimate revolutionaries all fought, across millions of familiar locations.
Unfortunately, this also kicked off many invasions, secessions, and other military ambitions. Charismatic people the world over tried to gather force, and many were swatted down either by each other or existing Government forces. Similarly, some places folded these empowered individuals into the police or military, although they could, in general, not be forced, except through fear.
The power that Domino's tokens bestowed was "One holographic device of any kind." It became quickly known, however, that a holographic implant which provided superpowers was considered "one device." It did not match up to the power that Domino Effect had (many tried, none came close to success), and in fact it usually only conferred one type of special ability. People with these implants were referred to by Domino himself as Archons, although they went by many common names (Supers, freaks, heroes, demons, monsters, angels, Tim, whatever).
Archons have a number of characteristics in common; they all are granted a limited visual enhancement (notably, this allows archons to write sigils only visible to other archons), are somewhat resistant to damage, and are capable of flight (although many aren't good enough to land without killing themselves, and not all are aware of the capability in the first place).
Additionally, Archons choose a special ability, usually some form of kinesis (pyro, cryo, etc). These powers are not related to the elemental abilities of the other setting (Draco, or the Terra-Draco settings later on); instead, they are increasingly sophisticated programs that evolve with the user's psyche. The better the character understands their ability, the more powerful their abilities become, and the more complex the abilities they can use are.
Archons are not invincible to small weapons fire, much less to stronger military holography. They are generally faster, and their ability to destroy is far higher. For those with certain powers, their ability to create or repair is also far higher; some use this to restore cities, heal people, and so on.
(Although it's assumed that Domino could bring back the dead if he really wanted, it's generally assumed that people past a certain point are gone for all intents and purposes. There are those who try to worship Domino, but nothing comes of it, and he makes an effort to dissuade them.)
It's iconic of this time period that food and shelter are no longer primary concerns of anyone, anywhere--there is enough holographic technology the world over to produce food and potable water from mud and fusion power, and given that sort of power, a roof over your head is nothing. This brought huge swaths of the planet out of poverty, while at the same time enabling psychos in the first and third world nations. Those who had previously had all that they needed to survive became feral, while those who had been feral with hunger and disease were content just to survive without fighting tooth and nail for it. (This is not entirely true in either case, but even partially true as it was, the irony was lost on nobody)
It is to be said that psychos with power were the exception, not the rule. The tokens that Domino spread around the world (dubbed "Pandora Keys" by the enigmatic Mr. Stage) were spread with a literal, mathematical randomness. Some people who received them discarded them; others hoarded or sold them; others used them to create machinery in some literal sense (usually production facilities, but also more transient things, like cars, spaceships, giant mecha, or bad approximations of androids. Unfortunately, Domino did not have the methods necessary for artificial intelligence, and so attempts at such failed in this period).
Even those who did accept the archon package did not tend to fall into the psychotic category as a rule. In particular, people who had any interest in fantasy, sci-fi, and role-playing would often request such things without considering the consequences, and while some of them would go mad or make horrific mistakes, most of them were not psychotic. Additionally, police and military the world over would often take such powers without debate, in order to improve their ability to defend and keep peace (or, in some cases, attack and destroy).
One thing missing from this setting is any sense of genetic or bodily manipulation. Although Domino allowed cyborg implants in some cases (generally, when an existing Archon gets another wish), he would not be party to anything related to chemical or biological weapons, genetic manipulation, mutations, etc. He was also not typically willing to grant mind-altering powers, and when he did, they only affected other Archons, not non-augmented humans.
In speaking of Domino, it would be remiss to mention his occasional interference. Typically, if any particular situation got out of hand (defined as thousands of casualties, or the threat of such), he or his Blackhats would intervene. He was also very quick to intervene when any post-nuclear-grade weapons were deployed, even if they were not based on his technology; these weapons could level cities or worse, and he did not suffer their use under any circumstances. (Although some had speculated that they were the sort of weapons his floating sanctuary, Blackhat City, was vulnerable to, this has been shown false more than once.)
Aside from that, most of the world saw little of Domino. When he did interfere, he made headlines the world over, but the rest of the time, there was more than enough going on locally to occupy any and every journalist. In particular, although he and his city were attacked a great many times by individuals, groups, and even militaries, few such events occurred in populated areas, and even fewer were recorded or reported.
Towards the end of the Pan-Terranic Wars, governments began being populated by increasingly militaristic Archons, and rebellions started getting put down with more severity. Given that what Domino was trying to achieved was in principle equality, he failed miserably.
And if it weren't for what happened next, ushering in the Second Age, that might have been the end of it...