The R-101C is a fully automatic, compact assault weapon commonly used throughout the Frontier.
— In-game description.
The R-101C (Compact) Carbine is a Pilot anti-personnel fully automatic carbine manufactured by Lastimosa Armory. The R-101C was the replacement for the older G2A4 Battle Rifle in the hands of the IMC, soon becoming the standard rifle used across the Frontier. Eventually, the rifle would breed two similar weapon systems based off the design - the R-201 Assault Rifle and the D-101 Longbow DMR. By the time of Titanfall 2, the R-101 appears to have been almost completely phased out in favour of the newer R-201.
The R-101C Carbine is a fully automatic compact assault rifle built with an extendable frame specifically for Titan pilots. The carbine is depicted to fire 8.19mm rounds with tungsten penetrators in a copper-jacket and a polymer cartridge. The frame is partially collapsible for easier storage while in the confines of a Titan or wallrunning.
Extremely versatile and user-friendly, the R-101C Carbine is the workhorse assault rifle of the Frontier. The weapon is most effective at mid-range, but is still somewhat competitive at close and long ranges, meaning the weapon fits any play style whether aggressive or defensive. Although the weapon has generous usability and adaptability to any combat scenario, it is inferior to Pilot weapons specifically built for close and long range combat. Despite these drawbacks, no Pilot weapon boasts better versatility than the R-101C Carbine, making it the perfect weapon for entry level Pilots and experienced alike.
The Holographic Combat Optical Gunsight has an open sight picture, making it easier to acquire and track targets, particularly in the vertical. The gunsight is fixed at 1.85X magnification, and includes integrated ammunition readouts.
The AOG, or Advanced Optical Gunsight, is fixed at 2.4X magnification, and includes an integrated "current magazine capacity" readout with a backup numerical display. The AOG is ideal for combat at extended range.
The R-101 returns in Titanfall 2's Colony Reborn update. Although it has a different aesthetic, it is functionally identical to the R-201 Assault Rifle. It's only major difference is that its default Irondot Sight has been replaced with an AOG scope. It otherwise is identical to the R201. The Quality Assured banner can be unlocked by getting the R-101 to Generations 2.9 (Standard), 3.9 (FIRE) and 4.9 (GOLD). Getting the carbine to level 20 will unlock the Symbiote Patch.
Originally, it was envisioned by the designers as a completely customizable and modular weapon, before they dialed the modularity back and made it into a simple assault rifle. Elements of this modularity can still be felt in the similar designs of the R-97 Compact SMG, C.A.R SMG, and the Longbow-DMR Sniper.
The R-101C was originally known as the RSPN-101, short for Respawn, which is a reference to Titanfall's developer Respawn Entertainment. The rear iron sight of the weapon bears the Respawn logo.
Like many weapons in the game, the R-101 has been nerfed in the fourth update of Titanfall. It is now harder to hit targets at long distances and it's magazines size has been reduced from 30 to 24.
At the start of the carbine's "deploy" animation, the gun's stock, handguard, and barrel are compacted and close to the gun's receiver until they are extended. It is easier to see this phase in slow-motion, due to the rapid deploy time. A similar animation is employed in Titanfall 2's V-47 Flatline.