The Lex is a powerful, accurate pistol that has a lower rate of fire and clip size. Very efficient at long range.
The Lex is a sniper pistol. It's the slowest firing side-arm in Warframe, but has high damage and very high accuracy. The Lex's damage output does not falter at long distances, making it a potent alternative to the Latron, Vectis, and Vulkar. It is capable of dispatching most light armored enemies with a well-aimed headshot.
Well equipped for medium to long range combat, and the Hawk Eye mod can increase zoom to effectively use as a pocket sniper.
At first the Lex will feel very weak, slow, and bulky. Upgrading it with a Catalyst and/or Forma is advised, as reload speed and fire rate mods are needed as well as damage and multishot.
Recommended to pair this with a close to mid-range primary weapon as its small magazine and longer reload times can be crippling at closer ranges. This weapon is also very useful while playing a support role for its obvious long-range capability and common ammo type.
Barrel Diffusion enables a 120% chance for additional projectiles without ammunition consumption (up to 180% and faster fire rate with Lethal Torrent). This, combined with Hornet Strike will cause damage rivaling most sniper rifles.
Using Gunslinger to increase the firing rate of the Lex makes it a viable weapon in almost any circumstance.
This weapon conjuncts great with automatic rifles / shotguns, as most of those weapons do not have sniping capabilities.
This weapon can also be a high-risk-high-reward alternative to pair with a sniper rifle, since it can be used to finish off heavy enemies usually in few hits, when you need to reload your rifle, or when you're being surrounded by lightly armored enemies.
Using Steady Hands (which reduces the recoil of pistols) can be very beneficial to the Lex, as the high recoil time between each shot could lead you to death.