Keno

A lottery-style game where players pick numbers from a large field (usually 1-80) and are paid according to how many match a random draw, typically at a very high house edge.

Definition

In Keno a player chooses a 'spot' count, say 4 to 10 numbers, from a field of 80, then 20 numbers are drawn at random; payouts scale with how many of the player's picks are hit, according to a fixed pay table. Keno is descended from Chinese lottery games and appears in casinos, online and in some state lotteries. Its defining feature is an unusually large house edge: pay tables are set so that the operator's takeout is commonly in the region of 20-35 percent and sometimes higher, far worse for the player than table games or slots. Because of this, Keno should be understood as slow, high-margin lottery entertainment with strongly negative expected value, not a strategic game where skill improves the long-run result.

Worked example

A player picks 6 numbers; the draw matches 4 of them, paying a modest multiple of the stake per the pay table, while over many rounds the high takeout steadily erodes the balance.

Why it matters

Keno is the clearest casino example of how much house edge a pay table can hide; learners learn to compare edges across games, and professionals see how pay-table design sets margin.

Related

Note: Keno house edges vary widely by pay table and jurisdiction; the commonly cited 20-35 percent-plus range is indicative, not a fixed figure for any specific game.