How to Mod Weapons in Fallout 3

Download and install the G.E.C.K. (see link under Resources), then open it.

Select ̶0;Data̶1; under the ̶0;File̶1; menu.

Check the box by ̶0;Fallout3.esm̶1; and select ̶0;OK.̶1;

Expand the ̶0;Items̶1; menu in the object window, then select ̶0;Weapon̶1; under the "Items" menu.

Look for the weapon you want to modify in the window to the right, or use the filter--located directly below the bar labeled ̶0;Object Window.̶1; Once you have found your weapon, double click on it to expand its properties.

Select the ̶0;Game Data̶1; tab and modify the properties you want to change:

By increasing ̶0;Health,̶1; you increase the weapon's durability, meaning its condition will degrade less quickly, and it will require repairs less often.

By increasing ̶0;Reach,̶1; you can increase the effective range of a melee weapon.

By increasing ̶0;Fire Rate,̶1; you can increase a weapon's rate of fire, meaning that the weapon will fire more quickly and go through ammunition more quickly.

By decreasing ̶0;Spread,̶1; and ̶0;Min Spread,̶1; you can increase a weapon's precision, ensuring that all of your shots will land closer together.

By increasing ̶0;Crit Dmg,̶1; you can increase the additional damage caused by a weapon whenever it inflicts a critical hit.

By decreasing ̶0;Value,̶1; you can make a weapon less expensive to purchase and repair. On the other hand, you will also make less money if you attempt to sell the weapon.

By increasing ̶0;Damage,̶1; you can increase the damage a weapon deals per hit.

By altering ̶0;Ammo Use,̶1; you can change the amount of ammunition a weapon uses per shot. Setting ̶0;Ammo Use̶1; to ̶0;0̶1; means that a weapon consumes no ammunition, meaning you will never have to reload.

By increasing ̶0;Crit % Mult,̶1; you increase the probability that a critical hit will occur. Setting this value to ̶0;100̶1; will cause the weapon to inflict critical hits with every shot.

You can also alter the ̶0;Crit Effect̶1; entry so that a weapon has a special effect occur whenever it inflicts a critical hit. ̶0;VictoryRifleKnockdownSpell,̶1; for instance, causes enemies to be knocked onto their backs whenever the weapon scores a critical hit.

Finally, under ̶0;Art and Sound,̶1; you can alter the ̶0;Projectile̶1; entry to change the type of projectile fired by your weapon. Simply by changing this one property, pistols can be made to fire grenades--or even nukes.

Select ̶0;OK̶1; when you are done making modifications.

Choose ̶0;Save̶1; under the file menu to save your weapon mod.

Use Fallout Mod Manager or the Fallout 3 launcher to activate your mod, and launch the game to test your weapon mod.