Triplanetary - Landing and Takeoff

[Tom H.]

Originally Posted by Desert Scribe

Hey Tom. If you're not too far north of Austin, maybe we can get together for a game sometime.

Hey Desert Scribe, thanks for the offer.

Right now, I'm pretty tied up with settling in from a big move, but we should keep in touch through messages for something possibly later in the year.

[Tom H.]

I found some discrepancies on how we all are interpreting the launch procedure.

This is causing a lack of clarity in techniques for leaving a planet, and an official clarification would be welcome.

The launch procedure is governed by two rule concepts.

1. The natural way the astrogation and gravity rules work.
2. The imposition and explanation of Landing and Takeoff constraints on p. 4.

I see three ways to interpret the launch procedure.

The ways depend on how you apply the fundamental gravity rule, see p. 3, to launch.

Gravity takes effect on the turn after an object enters the gravity hex.

1. Natural astrogation, ignore additional constraints
This method ignores the arbitrary rule that takeoff velocity is immediately cancelled.
Example.
Turn 1: Boost off planet into initial gravity hex. Velocity is 1 away from the planet.
Turn 2: Astrogation applies the gravity hex from turn 1, now the ship is velocity 0. But now it can burn a fuel.
This burn can put it into orbit, or have it escape into space altogether.
Consequences.
Entering orbit feels unnecesary unless imposed.
Discussion.
This may be more inline with the 2e version of the game as desribed by RogerBW earlier here.
I prefer this method.

2. Double launch gravity
This method respects the arbitrary rule that takeoff velocity is immediately cancelled, but then also applies a gravity effect to turn 2.
Example.
Turn 1: Boost off planet into initial gravity hex. Planetary gravity mandates velocity is now 0.
Turn 2: Astrogation applies the gravity hex from turn 1, now the ship is velocity 1 back into the planet. But now it can burn a fuel to avoid a crash.
The recommended course of action would be to enter orbit.
Consequences.

• Launch gravity is stronger because it is effectively applied twice: once immediately on launch and then again as it carries over into the next turn.
• You can't escape the planet on turn 2.
• This appears to make orbiting a planet to leave it a necessity.
• This allows for the peculiar, obscure escape of the planet described by HeatDeath here.

3. Preprocess launch gravity
This method respects the arbitrary rule that takeoff velocity is immediately cancelled, but then ignores any additional gravity effect applied to turn 2.
The assumption is that launch is a special case in which the gravity effect is taken "early".
Example.
Turn 1: Boost off planet into initial gravity hex. Planetary gravity mandates velocity is now 0.
Turn 2: Due to the launch special case, gravity is not reapplied now. The ship is still at velocity 0. But now it can burn a fuel.
This burn can put it into orbit, or have it escape into space altogether. (The rules seem to constrain you to orbit.)
Consequences.
This really plays out the same as method 1.
Discussion.
I believe that this is the way I assumed everything worked when I first played the training mission many moons ago.
I really just assumed you would somehow need to get into orbit on turn 2, and start the game from there.

Conclusion
I wonder if method 1 was the procedure for 2e. Maybe Steve liked how method 2 seemed to force you to enter orbit and based 3e on it. However, was he aware of the unusual consequence that HeatDeath discovered?

Should there be these two rule layers to takeoff:

1. Movement mechanics
2. Arbitrary orbit requirements

I hope this consolidates a lot of the ongoing debate about how takeoffs might be tweaked.

[Tom H.]

P.S.

I just wanted to summarize HeatDeath's launch technique.

With the Double Launch Gravity method in effect, the ship thrusts back close to the planet. It then allows the rapid accumulation of gravity hexes to whip the ship around and out the back side of the planet to escape.

[GranitePenguin]

A bit of necro-posting (I really should have tried playing this sooner), but I wanted to point out something

Originally Posted by HeatDeath

So now we're in hex X, with a vector E->X, but we're not quite free and clear of any gravity arrows.Our vector would takes us to hex T, but recall that we passed through hex F to get here. Adding hex F's gravity arrow puts us in hex Y. If we do nothing else (and I've done the math right) we will continue to coast 1 hexes per turn on this vector (1 "northwest"), through hex Y and beyond. We've escaped Earth's (or whatever planet's) orbit using only 1 point of fuel.

The bolded part of this is incorrect. We do not pass through F; we travel along the edge of F. The example of Weak Gravity explicitly calls this out as NOT being influenced by the gravity hex:

Note that the new course runs exactly along the edge of a gravity hex. The ship has not entered gravity hex III.

It's still a cool maneuver (I found something similar when trying to understand entering orbit).

[Steve Jackson]

Good hack - showing the gravity simulation is not absolutely rigorous - but the rule requirements for getting into orbit are the controlling factor here. Burn two points of fuel :)

[GranitePenguin]

Originally Posted by Steve Jackson

Good hack - showing the gravity simulation is not absolutely rigorous - but the rule requirements for getting into orbit are the controlling factor here. Burn two points of fuel :)

Assuming you mean this under "Takeoff and Landing":

By expending a point of fuel, the ship may enter clockwise or counter-clockwise orbit. On a later turn it may burn fuel to leave orbit to return to the planetary surface or venture into space.

"may enter...orbit" implies it's not a requirement to enter orbit first.

Additionally, what about using an Overload to take off from a planet? That would be another way to get away from the planet without being in orbit first. If you must be in orbit before any other maneuvers after taking off; the rules need to be explicit that's the case.

[J. Durr]

Originally Posted by GranitePenguin

Assuming you mean this under "Takeoff and Landing":

By expending a point of fuel, the ship may enter clockwise or counter-clockwise orbit. On a later turn it may burn fuel to leave orbit to return to the planetary surface or venture into space.

"may enter...orbit" implies it's not a requirement to enter orbit first.

I read that as meaning the choice is between clockwise or counter: "it may enter clockwise orbit, or counterclockwise orbit". Of course it doesn't make it 100% clear.

The movement system is elegant but takeoff is puzzling.

[HarbingerX]

Originally Posted by J. Durr

I read that as meaning the choice is between clockwise or counter: "it may enter clockwise orbit, or counterclockwise orbit". Of course it doesn't make it 100% clear.

The movement system is elegant but takeoff is puzzling.

I'm prepping to pull this off the shelf and ran into this long discussion and confusion about takeoff. So I'll necro this thread to provide my input. :)

Steve Jackson Games rules tend to be written in a conversational style which can sometimes cause confusion when people are expecting a exacting rule. The take-off rules are pretty clear when you understand that the paragraphs are conversational.

1. Turn one, you are boosted with a velocity of 1 into orbit which becomes a 0 due to the gravitation effects.
2. Turn two, you must burn fuel to accelerate and avoid crashing back into the planet.

That's it. Then the rules describes the typical case that you burn one fuel to orbit clockwise or counter-clockwise.

Your only other options are:

• accelerate directly away from the base. this burns fuel and keeps you stationary.
• overload to escape orbit immediately.

The first item is a legal but non-sensical thing to do, so not worth mentioning. The second is specific to warships and could have been mentioned, but wasn't. Again due to the conversational style of the rules.