Psyonix Studios, in partnership with Valve, recently announced that it will roll out a "Portal" expansion pack for "Rocket League" starting this week. Players will receive the freebies by simply completing matches.

"Obtainable by playing a full game of Rocket League, the official Portal items are potentially rewarded at the end of every match, win or lose," read a statement from Psyonix via Steam. "All you have to do is keep playing until the match ends and your chance to earn a new Aperture-themed goodie of your very own."

Players will get the following items at random after every match:

  •  Cake (Topper)
  •  Conversion Gel (Rocket Trail)
  •  Propulsion Gel (Rocket Trail)
  •  Repulsion Gel (Rocket Trail)
  •  Aperture Laboratories (Antenna)
  •  Cake Sticker (Antenna)
  •  Companion Cube (Antenna)
  •  Personality Core (Antenna)
  •  PotatOS (Antenna)

This isn't the only "Rocket League" content coming in December as the Winter Games Event as the Chaos Run DLC will also be arriving shortly.

Psyonix marketing executive Jeremy Dunham wrote on PlayStation Blog that the brand new Mutator is known as "Snow Day." It transforms the field into an ice rink and replaces the glowing orb with an equally massive hockey puck.

The seven winter-themed items include a Santa topper, a Xmas rocket trail and a Candy Cane antenna. Like the aforementioned free DLC, all players have to do is complete matches to get the items. Naturally, the chances of them dropping are lower compared to standard items. Furthermore, the Winter Games Event only lasts until early January. Players who unlock their desired items before the cut-off date can keep them forever. If not, they'll have to wait until next year to have another shot at the items.

Here are the Winter Games Event items:

  •  Xmas (Rocket Trail)
  •  Blitzen (Topper)
  •  Christmas Tree (Topper)
  •  Sad Sapling (Topper)
  •  Santa (Topper)
  •  Candy Cane (Antenna)
  •  Holiday Gift (Antenna)

Psyonix also announced via a YouTube video that a paid DLC called Chaos Run will be released in December 2015. The expansion pack contains items based on the "Mad Max" movies. Items included in the $4 Chaos Run DLC are as follows:

  •  Two New Battle-Cars, Ripper and Grog
  •  12 New Decals (six for each new Battle-Car)
  •  Two New Paint Types (Camo and Sun-Damaged)
  •  Two New Wheels (Ripper and Grog)
  •  Two New Rocket Trails (Sandstorm, Nuts and Bolts)
  •  Three New Toppers (Boombox, Cow Skull, Mohawk)
  •  Three New Antennas (Bomb Pole, Radioactive, Retro Ball - Wasteland)
  •  Five New Trophies

"Chaos Run" will also bring a free update that introduces a new arena known as "Wasteland." It's inspired from the arena of the same name from "Supersonic Acrobatic Rocket-Powered Battle-Cars." It's will also be the first "non-regulation" play space in "Rocket League."