Part III: Business & Regulation · Gambling Mathematics & Probability

PAR Sheet (Program Accounting Report)

Slot MathREPORTED

(1) A PAR sheet is the confidential game design document created by slot manufacturers that specifies every mathematical parameter of a slot machine, including the reel strip layouts, symbol frequencies, virtual reel mapping, paytable values, hit frequency, RTP, and volatility metrics. The PAR sheet is the “source of truth” for a game’s mathematical behavior: all actual outcomes are determined by the parameters it defines. Gaming regulators review PAR sheets during the game approval process to verify that the game meets jurisdictional requirements for minimum payout percentages. Casino surveillance and slot operations personnel may reference PAR sheets when investigating player disputes, alleged malfunctions, or unusual payout patterns. PAR sheets are considered proprietary trade secrets and are not publicly available. (2) A confidential mathematical document provided by the slot machine manufacturer that specifies the complete probability and accounting profile of a slot game. PAR stands for “Probability Accounting Report.” The PAR sheet details: the payback percentage (RTP), the hold percentage (casino’s theoretical win), the hit frequency, the symbol distribution on each virtual reel, the volatility index, and the confidence intervals for expected performance. It is the definitive reference for determining whether a machine is performing within expected parameters. Slot managers and compliance officers use PAR sheets as the benchmark against which actual meter readings are compared.

In practice

PAR sheets are proprietary and typically not disclosed to the public. Casinos must maintain them on file for regulatory inspection. A PAR sheet may span hundreds of pages for complex multi-feature games. “PAR” originally stood for “Program Accounting Report” or “Probability Accounting Report.” Each game title may have multiple PAR sheet versions with different RTP settings (e.g., 88%, 90%, 92%) that casinos can choose from. The term “PAR” also refers to the expected hold percentage (e.g., a 12% PAR means the game is designed to hold 12% of handle).

One entry from the Casino Industry Glossary, 1,090 terms written for surveillance, compliance and operations professionals rather than for players. Definitions describe industry usage; where a term carries a regulatory meaning, verify against the instrument that governs your jurisdiction.