Beginning today at 10am PT/1pm ET, Treyarch will be hosting an Arena Double-Double Weekend in Call of Duty: Black Ops 3, offering double multiplayer XP and double weapon XP in Arena mode on PlayStation 4, Xbox One, and PC until Monday at 10am PT/1pm ET.
Treyarch also announced today that they’re introducing Daily and Weekly Contracts, as well as the new character Blackjack, on June 14 for PS4, Xbox One, and PC.
As they explained, completing Daily Contracts gets you Cryptokey rewards, while Weekly Contracts offer up more Cryptokeys and the ability to activate Blackjack for a limited time:

Daily and Weekly Contracts
A Daily Contract consists of a single challenge that you must complete before the next day. Complete the Daily contract to get Cryptokey rewards. Daily contracts cycle every 24 hours at 10am Pacific Time. A Weekly Contract cycles every 7 days (Monday-to-Monday at 10am Pacific Time) and consists of two separate challenges. Complete both Weekly Contracts during this window of time to reap the rewards ? Cryptokeys and a special Mercenary Contract that can be activated to use Blackjack in-game.
The Black Market Vendor – Blackjack
Our Black Market vendor sits on the sidelines no more ? Internet famous and Reddit infamous, Blackjack is making his Multiplayer debut! Blackjack will now available for mercenary work.
Complete both Weekly Contracts and you will be rewarded with a Mercenary Contract that allows you to hire Blackjack for a limited time (60 minu...