Euclid's C-Finder

Euclid's C-Finder is a weapon in Fallout: New Vegas.

Characteristics
The raw power of the sun, contained in an easy-to-carry package! Just point this weapon at the bad guys, and pull the trigger! The ARCHIMEDES II orbital laser will strike down at the speed of light and reduce your foes to ashes. The weapon can only be used once each 24 hours because of the recharge time of the lasers. To use the C-Finder the player must complete That Lucky Old Sun and choose to direct power to ARCHIMEDES II at the end. Once that quest is complete, the power cannot be redirected; the player can choose to arm the ARCHIMEDES I defense system even after the quest has completed, but that is a separate system, not controlled with the C-Finder.

Locations
Found in Freeside, near the east gate. A boy named Max carries it. He is chasing a girl named Stacey. The player may either buy it for 1000 caps (or 20 caps with a barter skill of 45), or it can be pickpocketed from Max, or taken from his bedside while he is sleeping. Max goes to sleep at 9:30pm, and sleeps on the second floor of the building on the right after coming into Freeside from the East Gate.

Behind the scenes

 * Euclid was a famous Greek mathematician. Among other things, he discovered basic geometric principles such as conic sections.
 * The name of the C-Finder, and the graphics it shows the player while it is operating, are a reference to using Euclidean geometry to find the third point, C, of a triangle, given points A and B, and distances BC and AC. In this example B is the player's position on the ground, A is the position of the ARCHIMEDES II satellite, and C is the position of the target. The satellite gets distance BC from the C-Finder (which is described as a "handheld rangefinder," in the terminal notes at HELIOS One), and knows AC, one assumes, from radar height measurement. In fact in practice the satellite would need significantly more information about, for example, the direction the C-Finder was pointing, and given good direction and range information the handheld device could calculate the target position directly. Perhaps one is to assume that the C-Finder can only measure basic compass heading and range, leaving the satellite to calculate the target's elevation.

Bugs

 * Occasionally, it is possible to get another shot right after the first one is fired. This has been tested by targeting the sky, then targeting a ground target and sometimes another charge will be acquired right after.
 * Even though it states that the recharge takes 24 hours it is actually closer to something like 28 hours.
 * If you've already bought the gun from Max before the quest I Could Make You Care, you can buy it from him again.
 * You can get quite a bit of ammunition for the weapon if you take the NCR troopers service rifles after you activate the satellite while having the C-Finder equipped, this may also work with other weapons thus it allows you to use it as many times as you wish provided you had enough ammo and you do not have to wait 24 hours you can use it continuously in rapid succession.
 * When attempting to fire at any location, the game will freeze (after activating Archimedes II at Helios One). Usually related to having the perk 'Heave Ho!' Using the console to remove this perk will allow you to fire the gun without crashing.
 * When trying to fire, the targeting laser will repeatedly play its animation without the laser firing. This will prevent the player from both using the weapon and from getting a new charge. The animation will continue to play indefinitely. It sometimes fires awhile later at a random interval. This can be very inconvenient as it can kill the player, or if it fires inside a town, everyone in that town will turn hostile.
 * A fix is to save and quit the game, restart the game and load in the save. However: be warned, the animation will start straight away on loading but this time it will fire breaking the glitch. This can also result in the laser being fired directly at the player, upon start-up...
 * It is possible to obtain this weapon an indefinite amount of times. If the player pickpockets Max and then waits a few days, when going to pickpocket him again he may have another C-Finder.
 * Sometimes, if the player removes the gun from their inventory they will be able to buy it again from Max.

Appearances
Euclid's C-Finder appears only in Fallout: New Vegas.