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Last Updated: January 7, 2021

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Alien Attack Keno

Introduction

Alien Attack Keno is a keno variant by Action Gaming. It features a bonus and another bonus within a bonus themed with a battle between cows and aliens. At the time of this writing, the game can be found at VideoPoker.com, where a Gold level membership is required to play that game. I imagine it will be seen on casino floors beginning in early 2021.

Rules

  1. The base game is the same as conventional keno, which I assume the reader is familiar with.
  2. The player may choose 3 to 10 spots for the base game.
  3. The player will choose two Bonus Spots from among the numbers he didn't already pick for the base game.
  4. The game will draw 20 random numbers, as in conventional keno.
  5. If less than two of the Bonus Spots are hit, then the game is scored as in conventional keno.
  6. If both Bonus Spots are hit, then the player will play the Pick-a-Prize Bonus.
  7. In the Pick-a-Prize Bonus there is a grid of 19 icons, with the following distribution. Prizes are relative to the bet amount.

    Pick-a-Prize Bonus Prizes

    Prize Weight Probability
    1 11 0.578947
    2 1 0.052632
    3 1 0.052632
    5 1 0.052632
    10 1 0.052632
    15 1 0.052632
    Alien Attack 3 0.157895
    Total 19 1.000000
  8. If the player picks an Alien Attack, then he will play the Alien Attack bonus (a bonus within a bonus).
  9. In the Alien Attack bonus, the Bonus Spots the player should pick three numbers to mark with cows and three to mark with aliens. The player choose the numbers previously marked as Bonus Spots.
  10. The game shall pick 20 numbers, as in conventional keno.
  11. The player will always get paid on his base game picks in the Alien Attack bonus, as usual.
  12. If no cows or aliens are marked, then the free spin shall act like an initial spin.
  13. If the ball draw matches at least one alien and no cows, then the aliens will abduct one of the cows.
  14. If the ball draw matches at least one cow and no aliens, then the player will win a multiplier to be applied to the base game win. This multiplier is 2x for one cow hit, 3x for two cows hit, and 5x for three cows hit.
  15. If the ball draw matches at least one cow and one alien, then what I will call a "milk battle" will ensue. This is displayed as the cows hurling milk and cheese at the aliens. The number of shots fired by the cows will equal the product of the number of cows and number of aliens spots marked in the ball draw. Each shot fired shall award a random prize. The prize weightings depend on the number of cows remaining, as follows.

    Milk Battle Prizes

    Prize 1 or 2 Cows 3 Cows
    1 13 5
    2 3 4
    3 1 4
    5 1 5
    10 1 1
    20 1 1
    Total 20 20

    In addition, if the player has one or two cows, then with each shot fired there is a 60% chance at a cow rescue. The probability of a cow rescue is 12/13 if the Milk Battle prize was 1, otherwise it is 0. At most, one cow may be rescued per bonus game. Although the game presentation may show otherwise, the cow is not rescued until the end of the bonus game. In other words, the number of cows is taken as the total at the beginning of the bonus game.

  16. The bonus shall keep playing until the player has no cows left.

Pay Tables

At the time of this writing, I am aware of two pay table for Alien Attack Keno, as follows.

Pay Table 1

Catch Pick 3 Pick 4 Pick 5 Pick 6 Pick 7 Pick 8 Pick 9 Pick 10
0 0 0 0 0 0 0 0 0
1 0 0 0 0 0 0 0 0
2 2 1 0 0 0 0 0 0
3 15 4 2 1 1 0 0 0
4   35 15 4 3 2 2 1
5     225 64 8 8 5 4
6       400 105 60 8 5
7         750 230 66 37
8           1500 500 150
9             3000 700
10               5000

Pay Table 2

Catch Pick 3 Pick 4 Pick 5 Pick 6 Pick 7 Pick 8 Pick 9 Pick 10
0 0 0 0 0 0 0 0 0
1 0 0 0 0 0 0 0 0
2 2 1 0 0 0 0 0 0
3 19 4 2 1 1 0 0 0
4   51 19 4 3 2 2 1
5     225 80 12 9 5 4
6       400 122 72 15 9
7         750 240 80 38
8           1500 500 155
9             3000 700
10               5000

Base Game Analysis

The following table shows the number of combinations for each possible outcome by both number of picks and catches.

Base Game Combinations

Catch Pick 3 Pick 4 Pick 5 Pick 6 Pick 7 Pick 8 Pick 9 Pick 10
0 34,220 487,635 5,461,512 50,063,860 386,206,920 2,558,620,845 14,783,142,660 75,394,027,566
1 35,400 684,400 9,752,700 109,230,240 1,001,277,200 7,724,138,400 51,172,416,900 295,662,853,200
2 11,400 336,300 6,501,800 92,650,650 1,037,687,280 9,512,133,400 73,379,314,800 486,137,960,550
3 1,140 68,400 2,017,800 39,010,800 555,903,900 6,226,123,680 57,072,800,400 440,275,888,800
4   4,845 290,700 8,575,650 165,795,900 2,362,591,575 26,461,025,640 242,559,401,700
5     15,504 930,240 27,442,080 530,546,880 7,560,293,040 84,675,282,048
6       38,760 2,325,600 68,605,200 1,326,367,200 18,900,732,600
7         77,520 4,651,200 137,210,400 2,652,734,400
8           125,970 7,558,200 222,966,900
9             167,960 10,077,600
10               184,756
Total 82,160 1,581,580 24,040,016 300,500,200 3,176,716,400 28,987,537,150 231,900,297,200 1,646,492,110,120

The following table shows the probability for each possible outcome by both number of picks and catches.

Base Game Probabilities

Catch Pick 3 Pick 4 Pick 5 Pick 6 Pick 7 Pick 8 Pick 9 Pick 10
0 0.416504 0.308321 0.227184 0.166602 0.1215743 0.08826624 0.063747838 0.045790701
1 0.430867 0.432732 0.405686 0.363495 0.3151925 0.26646411 0.220665594 0.179571376
2 0.138754 0.212635 0.270457 0.308321 0.3266541 0.32814562 0.316426135 0.295256781
3 0.013875 0.043248 0.083935 0.129820 0.1749932 0.21478623 0.246109216 0.267402368
4   0.003063 0.012092 0.028538 0.0521910 0.08150370 0.114105182 0.147318897
5     0.000645 0.003096 0.0086385 0.01830259 0.032601481 0.051427688
6       0.000129 0.0007321 0.00236671 0.005719558 0.011479395
7         0.0000244 0.00016046 0.000591678 0.001611143
8           0.00000435 0.000032592 0.000135419
9             0.000000724 0.000006121
10               0.000000112
Total 1.000000 1.000000 1.000000 1.000000 1.0000000 1.00000000 1.000000000 1.000000000

The following table shows how much the base game return for each number of picks and catches for pay table 1.

Pay Table 1 Return

Catch Pick 3 Pick 4 Pick 5 Pick 6 Pick 7 Pick 8 Pick 9 Pick 10
0 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
1 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
2 0.277507 0.212635 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
3 0.208130 0.172992 0.167870 0.129820 0.174993 0.000000 0.000000 0.000000
4   0.107219 0.181385 0.114152 0.156573 0.163007 0.228210 0.147319
5     0.145108 0.198121 0.069108 0.146421 0.163007 0.205711
6       0.051594 0.076868 0.142003 0.045756 0.057397
7         0.018302 0.036905 0.039051 0.059612
8           0.006518 0.016296 0.020313
9             0.002173 0.004284
10               0.000561
Total 0.485638 0.492846 0.494363 0.493686 0.495844 0.494854 0.494494 0.495197

The following table shows how much the base game return for each number of picks and catches for pay table 2.

Pay Table 2 Return

Catch Pick 3 Pick 4 Pick 5 Pick 6 Pick 7 Pick 8 Pick 9 Pick 10
0 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
1 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
2 0.277507 0.212635 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
3 0.263632 0.172992 0.167870 0.129820 0.174993 0.000000 0.000000 0.000000
4   0.156233 0.229754 0.114152 0.156573 0.163007 0.228210 0.147319
5     0.145108 0.247651 0.103662 0.164723 0.163007 0.205711
6       0.051594 0.089313 0.170403 0.085793 0.103315
7         0.018302 0.038509 0.047334 0.061223
8           0.006518 0.016296 0.020990
9             0.002173 0.004284
10               0.000561
Total 0.541139 0.541860 0.542733 0.543216 0.542843 0.543162 0.542814 0.543403

Pick a Prize Bonus Analysis

The probability of earning the Pick a Prize bonus is (20/80)×(19/79) = 0.060127. If we count the value of the Alien Bonus separately and as zero for the Pick a Prize bonus, then the average win in the Pick a Prize bonus is 49/19 = 2.421053, as shown in the following table.

Pick a Prize Return

Win Count Probability Return
1 11 0.578947 0.578947
2 1 0.052632 0.105263
3 1 0.052632 0.157895
5 1 0.052632 0.263158
10 1 0.052632 0.526316
15 1 0.052632 0.789474
Alien Attack 3 0.157895 0.000000
Total 19 1.000000 2.421053

The contribution to the return for the Pick a Prize bonus is (20/80)*(19/79)*(49/19) = 0.145570.

Alien Attack Bonus

The probability of the Alien Attack bonus per initial spin is 0.009495.

The following details about the Alien Attack bonus is based on a random simulation of 10,260,500,000 pick-8 initial games and 97,422,443 Alien Attack Bonuses.

The average bonus game contained 12.429464 free games.

The average number of milk battles per bonus is 5.252288.

The average win per milk battle is 3.623039.

The average win from milk battles per Alien Attack bonus is 19.029241.

The average return from milk battles per initial spin is 0.180683.

The average base game win per Alien Attack bonus, including multiplier, is 7.689517.

The average base game win per initial spin, including multiplier, is 0.073011.

The average win per Alien Attack bonus is 19.029241 + 7.689517 = 26.718758.

The return from the Alien Attack bonus per initial spin is 26.718758 × 0.009495 = 0.253692.

Analysis Summary

The overall game return, for the 2-8-60-230-1500 pick-8 pay table can be broken down as follows:

  • Base game = 0.494839
  • Pick a Prize bonus = 0.145576
  • Alien Attack bonus = 0.253692
  • Total = 0.894107

It should be noted that the makers of this game claim a return for the same pay table of 89.467%. The reason for the 0.056% difference I attribute to random variance in the simulation.

Video

Please enjoy my video where I explain, demonstrate, and go over my analysis of Alien Attack Keno.


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