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RNG stands for Random Number Generator, a system responsible for generating a sequence of numbers to randomly determine card outcomes. In poker, RNG replaces the traditional human card shuffling. Players in poker rooms often claim that the generator is rigged, especially when they don’t receive nut hands or when they get a strong combination only to find their opponent’s hand is even better. In this article, we’ll explore what a random number generator is in poker, the types that exist, and why it’s used in all poker rooms.
RNG History
The first opportunity to play poker for real money online was offered by Planet Poker, which launched in early 1998. A lot of companies, including Cigital, were curious whether it’s safe or not. Employees at Cigital wanted to verify the reliability of the program’s algorithms, and in response to their requests—and to demonstrate confidence in its RNG—Planet Poker published its source code. It didn’t take long for flaws to be discovered.
The first problem security experts found was that during a random shuffle, the first and 52nd cads could never swap places. This seemingly minor detail caused a significant deviation from true randomness in the resulting deck.
The second major flaw was tied to the limitations of Pascal’s functions. Without diving into technical details, Planet Poker’s generator could produce no more than 86.4 million variations of a 52-card deck shuffle, far fewer than the real-world possibilities.
The third and fatal flaw was the ability to predict the full sequence of the dealt deck. By seeing three board cards and two hole cards, players could calculate their opponents’ cards, as well as the turn and river.
This fiasco dealt a serious blow to Planet Poker’s reputation and the industry as a whole. However, without this lesson, poker rooms and honest players might have faced significant financial losses eventually.
How RNG Works
The foundation of a reliable poker site is the unpredictability of card distribution. To ensure this, online poker rooms use RNG—a specialized hardware device employed across various industries, including everyday computing. Players don’t need to understand RNG to succeed, but knowing how it works can shed light on how fairness is maintained and cheating is prevented.
A Random Number Generator (RNG) is a computer program that creates random numerical combinations. There are two main types:
- Software-based. These pseudo-random generators produce number sequences based on a predetermined initial value. Since the starting point is fixed, the resulting combinations are also predictable.
- Hardware-based. These use varying initial values for each sequence, drawing from an entropy source for input data. In computers, this might include processor rhythm, board vibrations, etc.
Modern poker room RNGs typically combine software and hardware generator algorithms. Don’t confuse RNG with PRNG (Pseudo-Random Number Generator). The latter is predictable, and with effort, its algorithm can be cracked to forecast sequences. Thus, a PRNG can be “hacked”—its patterns deciphered to predict outcomes.
RNG in Poker Rooms
One of the primary responsibilities of any online poker room is ensuring the secure generation of random card sequences and reliable data transfer between the server and game client. This makes pseudo-random software generators unacceptable, as they’re vulnerable to hacking, allowing malicious actors to access number sequences—and thus know opponents’ cards.
To prove their RNGs are secure and reliable, poker rooms obtain certification. For example, PokerStars’ RNG is certified by Cigital, one of the world’s most reputable certification firms. For objective testing, RNGs undergo the NIST test suite, based on the U.S. FIPS 140-2 standard.
Random number sequences are generated using multiple entropy sources and a pseudo-random algorithm. At PokerStars, for instance, entropy comes from user behavior: mouse movements, screen clicks, decision timing, and more. This entropy is processed by Quantis’ hardware RNG, which outputs the numerical sequence. Random number flow can range from 4 to 16 megabits per second.
PokerStars also employs a concept of “sufficient randomness.” Until the system determines randomness is high enough, the deal won’t begin. If user data is insufficient to form a sequence, the deal is delayed—by mere fractions of a second, unnoticeable to players, but enough for the RNG to convert random bits into numbers.
Here’s how it works: to generate a number between 0 and 25, a counter selects 5 bits and converts them into a number from 0 to 31. If the result exceeds 25, the process loops until a valid number is obtained. This algorithm fully shuffles the deck, ensuring cards are dealt randomly.
Deck shuffling can occur continuously in real-time or once before the deal. The former is considered more secure, as each subsequent board card remains unknown until the last moment.
Live Card Dealing for Online Rooms
A lesser-known poker room in CIS region, Real Deal, took card shuffling to a new level. Instead of a traditional RNG, this online room used a physical shuffle machine to mix a real deck of cards, projecting the results onto the virtual table.
Patented as “Cut’N Shuffle,” this machine eliminates randomization issues, ensures deal security, and even lets players cut the deck if desired. Video recordings of all shuffles are stored on the room’s servers, accessible to any player. While this technology is still young and not widely adopted, it could gain traction in the future.
Blockchain in RNG
Coin Poker outpaced many competitors by open sourcing its RNG code in 2018. This cryptocurrency room introduced a decentralized generator, allowing players to participate in shuffling. Here’s how:
- Click the RNG button at the bottom of the table.
- Enter a password and confirm with OK. When the button turns green, you’re contributing to decentralized shuffling.
- After the hand ends, an RNG number appears. Click it to activate Hands Hindsight, revealing common cards and the full deck (minus opponents’ four hidden cards).
Coin Poker even held a $2,600 prize contest for anyone who could find flaws in its software. No one ended up taking the money.
Is RNG Rigged?
To wrap it all up, let’s address why no reputable poker room would tamper with its RNG to deceive players. Profit comes from rake—the commission taken from nearly every cash pot. The room doesn’t care who wins or loses; only the rake volume matters.
If you think the RNG feels rigged, recall how often you’ve won in similar situations or been the lucky one. We tend to take luck for granted but cry foul when it turns against us. Here’s a simple fact: there’s no direct evidence of rigged RNGs in poker rooms. In 99% of cases, the game is fair.
Why Players Don’t Trust RNG Fairness in Online Poker
Poker is a skill-based game where luck still plays a role. Any player can hit a streak of bad—or good—hands. Someone might even get two royal flushes in a row. Those enduring losing streaks struggle emotionally and doubt the online room’s fairness—a quirk of human psychology.
Does this relate to RNG? Not really. The generator treats all players equally, with no favorites. Inexperienced players often blame the machine for losses, ignoring variance—the deviation from mathematical expectation.
Statistically, about 70% of poker players lose over the long term. Losing is tough to accept, triggering what Sigmund Freud called a “defense mechanism”—blaming an external factor rather than oneself.
HisHands: Your Assistant in Analyzing and Adapting to RNG
The enhanced hand history mining service HisHands offers poker players a unique chance to analyze opponents’ actions based on real game data. By collecting and processing hand history statistics, HisHands reveals opponents’ habits, preferences, play styles, bluffing frequency, and strategy choices across hand stages in online poker. This is especially useful for spotting patterns that might go unnoticed during regular play.
The key advantage of HisHands is that it removes RNG influence from the analysis. The service provides objective, accurate data, letting players build strategies based solely on opponents’ actions. This helps adapt to their play styles, minimize errors, and make better decisions at the table.
Conclusion
RNG is a device that generates numbers randomly. It produces sequences that are converted into a virtual deck shuffle. Hacking a modern poker room’s RNG—or rigging it to favor certain players—is impossible. In today’s world, that’s nothing short of science fiction!
