Minimum and maximum possible scores in Space Alert

by Harry Altman

Note: In this article I will primarily only be considering Space Alert without its expansion, The New Frontier. This is because I do not at present own a copy of The New Frontier. I do have some familiarity with it, and will make some notes on it at the end; however, it would be difficult to conduct the same level of detailed analysis without first buying a copy.

In this article I would like to consider the questions, "What is the lowest possible surviving score in a game of Space Alert?" and "What is the highest possible score in a game of Space Alert?". (I like to say that dying is -∞ points, but that is not very interesting.)

Let's be clear on the parameters of the problem -- this is Space Alert without the expansion. 4 or 5 players may be used. The players are actively trying to achieve the lowest/highest score. Any deck of threats may be used, any set of trajectories, etc.; we assume we are allowed to rig all the decks (damage tiles, etc.) and that the players know in advance everything that will happen. The audio track must be one of the 8 normal missions provided.

Some terminology: Let's define the "threat count" of a mission to be the number of common threats plus twice the number of serious threats. (This is in fact the term used for it in the New Frontier rulebook.) This is a useful quantity, because serious threats of a given difficulty level are (with a few exceptions) worth twice as much as common threats of that same level. Furthermore, it is constant across mission types -- it's equal to 3 for the test runs, 5 for simulation or advanced simulation (6 with 5 players), 7 for a mission (8 with 5 players), and if we include the expansion, it's equal to 8 for the easier double-action missions (10 with 5 players), and 10 for the standard double-action missions (12 with 5 players). So for our purposes now this quantity will always be equal to 7 or 8.

The maximum problem

First, the maximum problem; this is the easier one. There's an obvious upper bound on the maximum possible score, which is 8*6+21=69. (8 threat count, times 6 points for destroying a yellow threat, plus 21 points from the window.) 69 points is a "perfect game"... but is it actually possible?

Well, after several hours of trying to construct such a scenario, I can report that the answer is yes. What follows is one solution. Note of course that there may well be other solutions that look very different.

We use 5 players and audio track 8. For the trajectories, we put T3 on blue zone, T6 on white zone, T4 on red zone, and T1 internally. For the threats, we have an Overheated Reactor at time T+3, a Psionic Satellite at T+4, a Nebula Crab at T+5, a Juggernaut at T+7, and a Scout at T+8.

Finally, the moves. Players will move in the order Red, Yellow, Green, Blue, Purple.
Turn 1: Red hits C, all other players change decks. (Green, Blue, and Purple are delayed.)
Turn 2: Red changes decks, Yellow hits B, all other players do nothing.
Turn 3: All players press C. (7 points.)
Turn 4: All players press C. (7 points.)
Turn 5: Red uses heroic B (the other side of which shows upper red). Yellow presses B. (Overheated Reactors destroyed.) Green moves blueward. Blue changes decks. Purple heroically rushes to upper blue. (Psionic Satellite reaches X. All players are delayed.)
Turn 6: All players do nothing.
Turn 7: Yellow moves redward; all other players press A. (Psionic Satellite destroyed; Nebula Crab takes 3 damage. Nebula crab reaches X.)
Turn 8: Red and Green move redward. Yellow and Purple change decks. Blue presses C. (Nebula crab reaches Y.)
Turn 9: Purple presses C; all other players press A. (Nebula Crab destroyed; Juggernaut takes 4 damage. Scout reaches X.)
Turn 10: Blue changes decks; Purple presses C; all other players press A. (Juggernaut destroyed.)
Turn 11: Red moves blueward; Yellow heroically rushes to lower white; Green presses B; Blue presses A; Purple moves redward. (Scout destroyed.)
Turn 12: All players press C. (7 points.)

I have not listed what the other side of each card does, but it's pretty easy to fill these in in a manner consistent with the contents of the deck.

The minimum problem

First, let's note some lower bounds. There's an obvious lower bound of -36, if the players take all the penalties and gain no points. It may seem like this should be 7*2-36=-22, because you get 2 points for surviving a white threat; however, one must remember that it's possible to survive the mission without destroying or surviving every threat, since one only counts as having "survived" a threat if it reaches Z. We can, however, make a lower bound based on this idea.

The longest trajectory, T7, is 16 spaces long; a threat needs to advance 15 spaces to reach Z. If it has speed 3 or more (let's assume everything is constant speed for now), it will assuredly reach Z regardless of when it appears. If it has speed 2, however, it will have to appear by turn 6 to reach Z; and if it has speed 1, it will never reach Z. One can come up with similar numbers for the other trajectories; I won't go into details here. Note that straight-up "speed 1" threats do not exist -- there are two "speed 1" threats, the Man-of-War and the Juggernaut, and both speed up. It's straightforward to compute numbers for both of these. (Be careful, the Juggernaut has the odd property that it sometimes arrives sooner on longer trajectories.) There are no threats that lose speed so these are not a concern.

Let's now analyze the audio tracks. We'll consider both what happens with only 4 players and with 5 players -- while having fewer threats may seem better for our purposes, let's remember that with 4 players, one can only get -8 points from knockouts, not -10. I will not go through the full analysis here, but after a bit of work, we find the following (not necessarily unique) minima for points let through:

Track 1: 10 points (put T7 on red); 12 points with 5 players.
Track 2: 12 points (put T6 or T7 on blue); 14 points with 5 players.
Track 3: 6 points (put T7 on blue and T6 on white, with T+6 being the Man-of-War); still 6 points with 5 players (put T5 on red).
Track 4: 10 points (put T7 on blue, with T+6 being the Man-of-War); 12 points with 5 players.
Track 5: 12 points (put T7 on red and T6 on white); still 12 points with 5 players.
Track 6: 12 points (put T6 on red); still 12 points with 5 players (put T7 on white).
Track 7: 10 points (put T7 on red and T6 on white); 12 points with 5 players.
Track 8: 6 points (put T7 on red and T6 on white, with T+5 being the Man-of-War); still 6 points with 5 players (put T5 on blue).

This yields a lower bound of -30 points. But in fact, we will see that -30 is not achievable. Let's consider -- achieving this requires knocking out all players. But there's not too many ways to do that in the base game. Especially since the threat that delivers the knockout must either be white, or else knock the players out without reaching Z. The only white threats that knock out are the Battlebot Uprising and the Commandos (both serious internal). The only threats that knock out without reaching Z are the Battlebot Uprising, the Executioner, and the Power System Overload (all serious internal).

(Note: Although it will not be relevant here, Executioner and the Power System Overload each lack the ability to knock all players out, and so if we are relying on one of them to deliver the knockout, we must have both. (Or rather, Executioner can knock all players out, but it can't both knock out all players and disable both battlebot squads.))

From this we can see that -30 is not achievable with track 8, since its only internal threat is a common threat, incompatible with the above. Track 3 can be ruled out for similar reasons. Thus -30 is not achievable. And since there are no common threats that knock out, one can deduce that -29 is not achievable either.

However, it turns out that -28 is achievable. We use 5 players and audio track 8. For the trajectories, we put T5 on blue zone, T6 on white zone, T7 on red zone, and T4 internally. For the threats, we have Hacked Shields (blue) at T+3, a Psionic Satellite at T+4, a Man-of-War at T+5, a Frigate at T+7, and a Gunship at T+8. I will not include the execution details here because they are mostly fairly obvious -- the gist of it is, pick up the battlebots, fiddle with the shields, then get knocked out. You need 2 shield up on red. Note also that you need exactly 2 shield up on white, which means first you'll have to hit B in lower red before filling up the white shield. Don't worry about the blue shield; it'll take care of itself.

Notes on variable-range interceptors

While the variable-range interceptor rules are only intended for double-action missions, many people I know play with them in all missions. However, this rules variant does not affect the maximum or minimum. It clearly cannot affect the maximum, but it could be used to knock two players out without a threat, potentially allowing a lower minimum. However, in fact, -30 and -29 remain unachievable, as you would still need at least one threat to knock the other three players out, and so the logic above still holds, so -28 remains the minimum.

Notes on The New Frontier

As noted above, I cannot presently conduct the same level of detailed analysis on The New Frontier. I can, however, make a few notes.

Notes on the maximum problem

The New Frontier raises the score for a "perfect game" from 69 to 90 -- or to 122 for a double-action mission. It does this in several ways:
  1. The inclusion of red threats; these are worth more points than yellow threats. A common red threat is worth 4 if survived (as opposed to 3 for yellow or 2 for white).
  2. The Data Analyst's basic action; use of this action gives you +1 point.
  3. The Data Analyst's advanced action; use of this action allows you to get up to 4 extra points.
  4. This one's not relevant to a perfect game, but it is technically a new way to get additional points. By using the Medic's or the Special Ops's advanced action against the Seeker, you can avoid being knocked out by it (though your battlebots will still be disabled). The Seeker is worth 15 points if destroyed instead of the expected 12 to compensate for the knockout effect, meaning you normally only get 12 points out of it despite its listed number being higher; this allows you to get 14 points out of it (with Special Ops) or 13 points out of it (with Medic). Of course, that's still less than you'd get from just destroying a serious red threat instead, so as noted, it's not relevant to a perfect game.
Thus, the new upper bound is 8*8+25+1=90 for a normal mission, and 12*8+25+1=122 for a double-action mission. (Note that we get only 1 point from the Data Analyst's basic action, not 2, as we are also using the Data Analyst's advanced action.) It is not at all clear, however, whether scores of 90 or 122 are actually achievable. Analysis of that will have to wait for a later time, though.

Notes on the minimum problem

What about the minimum? In the base game, we had an absolute lower bound of -36 based on getting only penalties; a lower bound of -30 based on analyzing the audio tracks, trajectories, and threat speeds; and an actual minimum of -28. The expansion affords us several ways we might lower all of these. Let us address them in reverse order.
  1. The Plasmatic Fighter; the Plasmatic Fighter can knock people out, but is a white common threat.
  2. More slow threats; the expansion adds in more threats that have an initial speed of 1. If I recall correctly, they all speed up later, but these should still be useful for lowering point values, just as the Man-of-War is. Many are yellow or red, but in this context that doesn't matter.
  3. In a double-action mission, variable-range interceptors can be used to have a player knock themself out without the aid of a threat.
  4. Calling in threats. Several of the serious red threats call in another threat; these threats are only worth the points of a red common threat (4/8) instead of a red serious threat (8/16). This is still too many points to be helpful for this, but it's worth noting. A called-in threat may not appear until quite late, making it easy for it to be neither destroyed nor survived. However there is one case that is helpful...
  5. The Sealed Capsule. The Sealed Capsule is the one red common threat that calls in another threat; it is worth no points at all. (Yellow and white threats never call in other threats.) This, unlike the ones above, does seem helpful for reducing one's score. Especially because, once again, the called in threat may not appear until quite late.
  6. The Hypernavigator's basic action; the Hypernavigator's basic action can be used to have threats move one less space that turn. The application is obvious.
  7. The Hypernavigator's advanced action; this allows the ship to jump to hyperspace after turn 10 or 11 instead of 12 (although there is always a "turn 13", no matter what). The application, once again, is obvious.
  8. The Medic's advanced action; use of this action costs you 1 point.
So, #1 probably allows us to achieve -30, and #2-#7 probably allows us to achieve -36; indeed, they seem like overkill for achieving -36. Finally, #8 should allow us to achieve -37. I have, of course, not checked that -37 is actually achievable -- that will have to wait for a later time -- but I strongly suspect that it is.