A Knife, or known primarily as a Combat Knife or Fighting Knife is a cutting weapon designed for military use, specifically for close combat; however, since the end of trench warfare, most military knives have been primarily designed for utility/tool use (clearing foliage, chopping branches for cover, opening ammunition crates, etc.).
The Knife is an available weapon for all Operators in Tom Clancy's Rainbow Six Siege. It serves as a backup weapon in the event that a player has run out of ammunition or is engaged in close quarters combat. The knife kills all enemies in one hit should it make contact.
If used on a destructible surface, the Knife will leave a small hole on the surface allowing Operators to peek through.
- If a melee attack is used close to an environmental surface, a melee attack using the equipped weapon's buttstock is usually performed. However, it is functionally identical to a melee attack performed with a Knife.
- Zero is equipped with a Karambit which is prominently featured in several installments of the Tom Clancy's Splinter Cell Franchise. Despite this, it is functionally identical to the regular knife.
- Aruni replaces the knife with her prosthetic limb. Her melee attack is able to create larger holes in soft surfaces as well as destroy Hatches, Barricades and Castle's Armor Panels in one hit.
- Melee Attacks can shatter the glass found on Mira's Black Mirrors, Bulletproof Cameras, and Maestro's Evil Eyes.
The REACT Blade is a weapon featured in Tom Clancy's Rainbow Six Extraction. The weapon functions in a similar manner to its counterpart in Tom Clancy's Rainbow Six Siege. Additionally, when used on an Archæan from behind, the player will perform a Takedown with the blade, silently killing the enemy instantly.