Block: Impeding an opponent through use of position, hitting and leaning.

Blocker: Any one of four skaters for a team to start behind the pivot line but in front of the jammer line. Blockers are the offense and defense of the game, trying to assist their jammer through the pack while hindering the opposing jammer.

Calling the jam off: A jammer who has earned and continues to retain lead jammer may call the jam off before the two minute jam clock expires by repeatedly touching her hands to her hips.

Cougar: Intentionally picking up a fourth minor and subsequent trip to the box. So called because of the pop-culture reference of a "cougar" -- an older woman who seeks the sexual companionship of younger males. So intentionally going after a fourth "minor" is now called cougaring.

Goat: When blockers successfully trap an opponent in the back of the pack to slow the tempo of the jam, usually to help their jammer score points faster.

Grand slam: See POINTS. A grand slam is awarded where upon a jammer scores five points, four for each blocker and successfully lapping the jammer. A jam ref usually signals to the other jam ref if a jammer is being lapped by tapping on their helmet. The scoring jam ref will signal five points with his hand when reporting the points. Sometimes called "the five finger special."

Jammer: Designated by the star helmet cover, she is the only skater on the track that can score points for her team.

Jam ref: Each jammer is designated one jam ref per jam, using colored wrist bands in relation to the jammer's helmet or jersey color. Jam refs call "lead jammer," assess penalties to the jammer and keep track of scoring per pass -- reporting the score to the score table.

Lead jammer: The first jammer to break through the pack on her first lap legally is designated as lead jammer. This is designated by two whistle tweets from her respective jam ref, the jam ref pointing at the lead jammer and making an L shape with the free hand.

Pack: Defined as the largest group of blockers with a representative from each team within 10 feet of each other. Pack refs define the pack by holding their arms out and saying "Pack is here."

Pivot: A specialized blocker who wears a striped helmet cover. Pivot's get priority when lining up, usually opting to be the lead skaters in the pack. Pivots may also receive a "star pass" from their jammer, making them the new jammer. Pivots are often considered the leaders on the track, calling out plays and controlling the speed of the pack.

Point: Points are earned by legally lapping opposing players on a jammer's scoring pass. Points are awarded after the jammer exits the pack or once the jam has ended, usually by the jam ref signaling with his hand holding up one to five fingers. A jammer does not need to be "lead jammer" to earn points.

Poodle: Intentionally picking up a fourth minor and subsequent trip to the box. Partially credited to British slang and a reference to orientation within a sub group. A "bulldog" is considered a butch term, whereas "poodle" is considered submissive. A "poodle" in roller derby is submitting themselves for a fourth minor.

Star pass: When a jammer legally hands the star helmet cover to his/her teams respective pivot. Upon donning the star helmet cover (over the pivot cover) the pivot becomes the new jammer and continues the score pass where the preceding jammer left off.