Is "ORBA" an Acronym?
"ORBA" stands for "Oscillating Retro-Binocular Apparatus", or whatever else you want it to stand for. So anyway, yes, it's an acronym.
What Exactly is ORBA?
ORBA is a "tabletop / pen-and-paper" roleplaying game (RPG) system. An RPG system is a set of rules constructed for the purpose of playing RPGs.
More specifically, ORBA is a universal RPG system, meaning it's not intended for use with any particular genre or setting. And if needed, it can be easily modified to suit your needs.
What is an RPG?
A roleplaying game is essentially a way of playing "pretend" like you used to when you were a child. You pretended to be someone else at another time and place, perhaps even in a whole other world. You might've pretended to be a soldier, policeman, firefighter, professional athlete, knight, astronaut, or whatever else. You might've even pretended to be a specific person you wanted to emulate, someone who was a hero to you.
RPGs are a way of allowing you to continue such pretending despite being a teenager or adult. They serve as a more structured, predictable form of playing "pretend" more suited for teens and adults than children.
How Do You Play an RPG?
In a standard RPG there is a gamemaster (GM) and one to four or five players. The players each create a player-character (PC) for them to play (or pretend to be, or roleplay) in the world provided and "run" by the GM.
The GM designs and writes an adventure for the PCs to go on, pretends to be (or roleplays) all the non-player-characters (NPCs), tells the players what happens when their PCs do things, and acts as an arbiter between the players.
Being a GM can be a lot of work, but someone has to do it, and it can still be lots of fun!
But those are just the very basics. Beyond them every RPG does things at least a little different. ORBA is just one way of playing an RPG.
What Will I Need to Play ORBA?
Firstly, to play ORBA you'll need at least two people: one to be the GM and one to be a player. Ideally, you'll want at least five players: one to be the GM and four to be the players.
Secondly, you'll need at least one six-sided die (d6), but you'll want more than that. The more the merrier.
Thirdly, you'll need some pens or pencils and some writing paper. These are for keeping track of what you'll need to remember while playing.
Fourthly, you'll need tokens to represent heroes, and at least eight tokens to represent NPCs.
Fifthly, you'll ideally need poster-sized sheets of paper or a fairly large dry-erase marker board upon which to draw a map. This isn't really needed but it makes ORBA easier and more fun.
As for the time needed to play, you'll need a minimum of about thirty minutes. However a typical RPG session (regardless of being ORBA or not) can run anywhere between two and six hours!