The Special Weapon Operation Reactional Deployment System, also known as SWORDS or the SWORD, is a UNSC Weapon modification system. Using Misriah Rails mounted on firearms, every UNSC operator can modify his weapon to match the needs of the current conflict or situation. This allows a simple assault rifle to vary between a close quarters assault rifle to a designated marksman rifle or grenade launcher. Most firearms have a 'set' equipment list, and anything else must be requested through the armoury. While the UNSC issues the vast majority of gear, many more modifications can be bought for 3rd party manufacturers for very specific performance properties.