The RX-78NT-1 Gundam NT-1, nicknamed Alex, was a Newtype-use mobile suit created by the Earth Federation Forces. It was introduced in the OVA Mobile Suit Gundam 0080: War in the Pocket.

By the time of the One Year War, the Principality of Zeon's lead Newtype researcher, Dr. Flanagan, had been conducting his research for more than ten years. In contrast, the Earth Federation Forces only began their Newtype research in August, U.C. 0079. This was because the EFF did not see the military value of Newtypes due to the small number of examples and low replicability.

However, concepts similar to Newtype-use unit were still included as part of the RX Project. Based on existing research to improve mobile suit responsiveness, as well as reports from the Newtype pilot Amuro Ray and operating data from the RX-78-2 Gundam, the EFF began the development of a Newtype-use mobile suit with the goal of improved durability and responsiveness. For this purpose, the fourth RX-78 series unit was redesigned as a custom unit for Amuro Ray and received the new model number of RX-78NT-1.

The Gundam NT-1's development was carried out by the Augusta Base, originally a facility that researched issues relating to soldiers' mental health, it was chosen because some of its researchers published essays proving the Newtype concept. For additional protection, it was equipped with a set of optional Chobam armor, earning it the nickname "Alex", which was derived from the model number prefix "RX" and the acronym "Armor Layered EXamination", the project name of its armor.

To ensure the extra weight from the Chobam armor does not hinder its mobility, the NT-1 was designed with expanded propellant capacity in mind. Inspired by the Zeon concept of using the leg itself as a large vernier unit, it was fitted with propellant tank/sub-thruster hybrid units on its legs. It was also fitted with a large number of additional thrusters, both to improve its mobility and to compensate for the added weight of its armor.

Thanks to its magnet coating and the use of a high-speed, large-capacity learning computer more advanced than the one used by the RX-78-2, the NT-1's responsiveness was more than three times that of existing mobile suits. In addition, it was also equipped with a panoramic cockpit and linear seat, two features that would eventually become standard on mobile suits, under the belief that they would enable a Newtype pilot to better make use of their expanded awareness.

Finally, based on analysis of combat data from the RX-78-2 Gundam, it was pointed out that the loss or damage of hand-carried weapons may impact the mobile suit's combat ability, so the NT-1 was equipped with a pair of concealed 90mm Gatling Guns in its forearms.