Ace Invaders

Introduction

Ace Invaders is a video poker variation in which the player may play three lines and gravity will pull down any aces if they help the hand immediately below. The game can be found at various casinos in Las Vegas. I know that Treasure Island has the game, which follows pay table D.

 

 

Rules

 

1. The player shall choose between 1 or 3 lines, and 1 to 5 coins per line.
2. Only if the player makes a max bet (15 coins) will a royal pay 4000 coins. Otherwise a royal will pay 250 times the bet on the given line, except under pay table A a royal will pay 200 times coins bet with less than max coins bet.
3. Cards for each line shall be dealt from an independent deck. In other words the game uses three decks, one for each line.
4. If the player chooses to play one line then the player will get one deal and one chance to discard on that line. No other lines will be active. The game will play like standard video poker.
5. If the player chooses to play three lines then the player shall first get five cards on the lower line. The player may then keep or discard any set of these cards. Then the top and middle line shall receive five cards each and lower line will receive replacement cards. Any aces from the top line can reproduce themselves and drop to the same position on the middle line, only if the drop will improve the score of the middle line. Then any aces on the middle line (including new ones that just dropped) can reproduce and drop to the same position on the bottom line, only if the drop will improve the score of the bottom line.
6. The program will check all possible combinations of ways to drop aces and elect the one that results in the greatest win in the hand directly below.
7. In the event aces can be dropped different ways, resulting in the same pay the hand directly below, then the way with the greater number of aces will take priority. One result of this rule is aces dropping on aces. Another effect of this rule is when both a straight flush or four aces can result from the ace drop, in which case the drop will form four aces.
8. In the event aces can be dropped different ways, resulting in the same pay the hand directly below, and the number of aces in each drop is equal, then the drop with the left most aces will take priority.

   For example in the following hand it makes a big difference which ace drops from hand 3 to hand 2. Either ace in hand 3 can complete the straight in hand 2. However if the ace of hearts falls it will fall again to hand one, creating four aces. However the ace of spades will fall because it is further to the left, and will not improve the bottom hand because there is already an ace in the first position.

    

   Hand 3	As	2c	Js	Ah	5d
   Hand 2	4c	2h	3d	4h	5s
   Hand 1	Ah	Ad	3c	2d	As

    

9. In the very unlikely event an ace drop can create either a staight flush or four aces (both of which pay 50 times the bet on that hand) all four aces will drop.
10. In addition to aces a royal flush (dealt or created on middle line) will also drop if it pays more than the hand below.

 

In the picture below you can see the two aces in the middle row dropped to the bottom row, forming three aces with the ace already there.

 

 

I'm told that the following pay tables are made available to the casinos.

 

 

One Row Analysis

The next table shows the return playing only the bottom line, which would be exactly the same as conventional video poker. Remember, a royal always pays 250 times coins bet if one line is bet, except under pay table A, which pays 200 times coins bet.

 

 

Three Row Analysis

The next table is the return table under pay table C for the top hand when playing three hands.

 

 

The next table is the return table under pay table C for the middle hand when playing three hands.

 

 

The next table is my original return table under pay table C for the middle hand when playing three hands. The lower right cell shows a total return of 2.072768. Leading Edge Design claims the return for the bottom hand is 2.076026, which I do not disagree with. So please take this table with a grain of salt.

 

 

The next table summarizes the return for all three rows, the value of the royal drop, as well as the overall return, which is the sum of the four columns, divided by 3.

 

 

Strategy

The following table shows the strategy in a three-hand game based on pay table C. To use the strategy look up all viable ways to play the bottom hand and choose the one highest on the list. The expected value is that for the bottom hand only. The player can not control the outcome of the top two hands. This strategy should only be 0.01% less than optimal.

 

 

Play for Free

The game makers, Leading Edge Design, has a very well done demo on its web site. No registration required, just start playing.

Methodology

I was hired to analyze this game in 2002. The analysis was so complicated I don't care to try to explain it here. My original return was about 0.1% lower than that claimed by Leading Edge Design, disagreeing only over the bottom hand. I tend to trust the LED numbers over mine in this case, so I inflated my bottom row returns to match those by LED.

Written by: Michael Shackleford