manufacturer in allowing the player to take as many of the possible lines on offer as desire – the long-term return to the player will be the same. The difference for the player is that the more lines they play, the more likely they are to get paid on a given spin (because they are betting more). To avoid seeming as if the player's money is simply ebbing away (whereas a payout of 100 credits on a single-line machine would be 100 bets and the player would feel they had made a substantial win, on a 20-line machine, it would only be five bets and not seem as significant), manufacturers commonly offer bonus games, which can return many times their bet. The player is encouraged to keep playing to reach the bonus: even if they are losing, the bonus game could allow them to win back their losses. Random number generators All modern machines are designed using pseudorandom number generators ("PRNGs"), which are constantly generating a sequence of simulated random numbers, at a rate of hundreds or perhaps thousands per second. As soon as the "Play" button is pressed, the most recent random number is used to determine the result. This means that the result varies depending on exactly when the game is played. A fraction of a second earlier or later and the result would be different. It is important that the machine contains a high-quality RNG implementation. Because all PRNGs must eventually repeat their number sequence and, if the period is short or the PRNG is otherwise flawed, an advanced player may be able to "predict" the next result. Having access to the PRNG code and seed values, Ronald Dale Harris, a former slot machine programmer, discovered equations for specific gambling games like Keno that allowed him to predict what the next set of selected numbers would be based on the previous games played. Most machines are designed to defeat this by generating numbers even when the machine is not being played so the player cannot tell where in the sequence they are, even if they know how the machine was programmed. Payout percentage Slot machines are typically programmed to pay out as winnings 0% to 99% of the money that is wagered by players. This is known as the "theoretical payout percentage" or RTP, "return to player". The minimum theoretical payout percentage varies among jurisdictions and is