Raise (Poker)
When a player bets more that the required bet.
 
Rake (Poker)
The money that the casino takes out of the pot to make money

Random Number Generator
A computer program designed to generate random numbers. Also known as RNG and are found in games such as slot machines and used by online casinos.

Rank (Poker Games)
The value of a hand compared to other hands

Rating
A method the casinos use to evaluate players action for comps

Reels (Slot Machines)
The spinning section of a slot machine. Can be virtual video reels

Ring Game (Poker)
A non tournament game of LIVE poker such as Texas Holdem

Risk of Ruin
A term that defines the chance of losing ones entire bankroll on a particular game

RNG
The Random Number Generator found inside all modern day slot machines

Royal Flush (Poker Games)
The highest poker hand. Consists of and Ace high straight flush