The R-9A2 Delta is the titular protagonist of the 1998 Shoot 'Em Up video game R-Type Delta. It is a R-Craft created to replaced the severely damaged R-9A Arrowhead following the events of R-Type, and acts as a predecessor to the more advanced R-9C War-Head. It pocesses a unique weapon that its predecessor did not: the Delta Weapon, which allows the craft to eliminates all smaller Bydos and severely damages larger ones (including bosses).
Following the events of R-Type, the R-9A Arrowhead successfully returns back to headquarters, but because the resulting war left the iconic craft severely damaged, it is quickly retired from service, and its parts are stripped for further research in future Bydo confrontations. The Space Corps begins research on a newer, stronger craft that can continue doing what the Arrowhead started, and after numerous tests, a potential prototype called the R-9A2 Delta is created. This new craft is fitted with the more powerful Diffusion Wave Cannon that the Space Corps was testing at the time, as well as a unique weapon called the Delta Weapon, which is capable of eliminating multiple Bydos at once.
One year later however, the Moritz-G, a large orbiting defensive weapon created by the humans is manipulated by the Bydo Empire, and begins a potential strike against Earth. Despite the fact that the R-9A2 Delta was still going through test trials, the Space Corps decides to released the craft into service under an emergency protocol in an attempt to counter the Bydo invasion, alongside two other experimental crafts the R-13A Cerberus and the RX-10 Albatross.
The Delta successfully proves that it is more than up to the task of destroying the Bydo Empire, and completes its mission by destroying the Bydo Core, alongside the Cerberus and the Albatross, but as a result, a large chain reaction occurs, causing the dimension that the crafts are in to begin to explode. The R-9A2 Delta, alongside the RX-10 Albatross successfully escape, but the R-13A Cerberus is not so lucky and gets trapped in the dimension and is presumed destroyed for nineteen years.
After completing its mission, the R-9A2 Delta was updated further, eventually influencing its technology into the later R-9C War-Head, which would prove useful in a second Bydo war.
The R-9A2 Delta shares many weapons similar to its predecessor, however it also boasts several unique armaments such as the new Delta Weapon and an updated and more powerful version of the Wave Cannon.
- Vulcan Cannon - a standard, rapid-fire capable cannon that can eliminate most small Bydos easily.
- Standard Wave Cannon - a powerful charging cannon that is capable of decimating multiple Bydos in its path, as well as being capable of dealing massive damage to larger bydos and bosses.
- Diffusion Wave Cannon - a stronger variant of the Wave Cannon unique to the Delta, which allows the craft to charge the Wave Cannon longer for an even more powerful blast (indicated by the Wave Cannon Meter turning from green to orange). The resulting shot fires seven bolts: one traveling straightforward, and another three traveling upwards and downwards respectfully, eventually causing all their trajectories to cross soon afterwards. The blast does more overall damage than the Standard Wave Cannon, and covers a larger area too, making it useful against large groups of enemies, although its usefulness becomes negated in small corridors.
- Standard Force - a powerful mechanic consisting of a Bydo embryo restricted within four control rods, the force can be "thrown" by the R-9A2 Delta, allowing it to deal contact damage. While separated from the craft, the force will fire independently, increasing for every Laser crystal the Delta obtains until it has reached full power. When connected to the Delta, it allows the craft to fire a powerful laser. Depending on the color of the crystal the Delta obtains, the weapon will be one of the following:
- Air-to-Air Laser (Red) - fires a powerful, penetrating laser consisting of one red and blue unit, at full power, the two lasers will begin to intertwined, allowing them to cover a wider area
- Reflective Laser (Blue) - fires three penetrating beam-type lasers, with the top and bottom lasers traveling in a 45 degree angle. The lasers are noted for their ability to bounce off walls, at full power, the lasers become longer.
- Air-to-Ground Laser (Yellow) - fires two powerful beams that travel upwards and downwards respectively before hitting a surface, which upon contact, will begin to travel across the ground, destroying anything within its path. At full power, the lasers will become longer.
- Delta Weapon: Nuclear Catastrophe - a unique weapon developed for the R-9A2 Delta, it allows the Delta to charge up a dosage gauge that when full and activated, will create a large nuclear explosion that destroys all smaller Bydos and severely damages larger Bydos and bosses instantly.
- Homing Missiles - obtained when the Delta collects a crystal with a red "M" on it. When used, the Delta will fire two missiles that will track the nearest enemy and damage them. They have high accuracy, but deal low damage.
- Round Bit Devices - the Round Bits act as a small, shield-like device that absorbs weaker enemy fire. They are indestructible so long as the Delta is not destroyed, but do not provide any firepower in most cases save for the Air-to-Air Laser.
- Speed Up - when the Delta obtains a crystal with an "S" on it, it will increase is its overall speed by one unit for a maximum of five. One must be careful not to obtain too many, it will make the Delta harder to control.