Hardline is a perk in Call Of Duty Black Ops and MW3. It allows the player to get a Killstreak with 1 less kill. Most players on MW3 use this for assualt or specialist killstreaks rather than support ones.
The MW3 hardline pro adds 2 things. The first is every two assists counts as 1 kill. The next is death streaks now are required 1 less death to activate.
Black Ops VersoinEdit
On Black Ops the Pro adds the ability to change the contents or a care package.