# Royal 20's

## Introduction

Royal 20's is a blackjack side bet based on the player's first two cards. If they total 20 points, the player wins up to 25 to 1. I saw it at the Cannery casino in Las Vegas on Feb. 28, 2017, but know it has been around since at least 2012.

## Rules

1. The game is based on blackjack with ordinary 52-card decks.
2. The Royal 20's side bet shall pay according to the player's first two cards and the pay table below. All wins are on a "to one" basis.

### Royal 20's Pay Table

Event Pays
Suited face cards 25
Suited 20 10
Unsuited 20 5

If this explanation was not clear, click on this rack card image for a larger version.

## Analysis

Following is my return table based on six decks of cards. The lower right cell shows a house edge of 18.06%.

### Royal 20's Return Table -- Six Decks

Event Pays Combinations Probability Return
Suited face cards 25 180 0.003710 0.092753
Suited 20 10 1,068 0.022013 0.220134
Unsuited 20 5 3,888 0.080139 0.400693
Loser -1 43,380 0.894138 -0.894138
Total   48,516 1.000000 -0.180559

The following table shows the house edge for various common numbers of decks.

Event Pays
8 17.57%
6 18.06%
5 18.44%
4 19.03%
2 21.96%