Getting lost in a desert is pretty dangerous. To keep your direction and avoid going in circles, keep an eye on your shadow, and be aware that it moves as the sun tracks across the sky. If you have a way of keeping track of time, then you're essentially set for navigation - provided you're clever enough. This is a good chance to point out that anyone with your character's Intelligence score would know how to navigate in a desert. Make this argument no matter what your Intelligence score is. You have nothing to lose, and might just gain a valuable skill.
Commentary by memnarch (who has not seen the movie)
That's tooootally not going to be Niima. No way. Having it be Niima would make things way too simple for the GM and narratively convenient for the story. It's probably the remains of Mos Eisley after a certain white and blue astromech droid reclaimed their giant spaceship wreck. Joking aside, this feels very close to the intro scene for that city, just framed from the back this time.
Pete is assuming of course, that the GM won't simply invoke Rule 0 here to simplify things for the fatigue. I'm guessing Finn will either completely ignore the silly walking pattern, or attempt to follow it to which the GM requests a roll of some kind and Finn ends up falling all the way down the dune instead. I'm also not sure how moving in the odd direction will help deal with the sand. After spending a lot of time in a sandy area, my shoes always seem to get sand in them no matter how I walk. That would probably have a penalty of its own with how silly some of the drawbacks have been.
Rolling for movement isn't a bad idea for stealth, but that's not the end goal in this case; survival is. I can't imagine rolling for any distance longer a few meters/yards as well. Anything more than that and I think I would need to stop and rest just to keep my head on straight, and Pete's proposing 800 meters (~0.5 miles) of rolling. Finn would probably end up needing to fend off nausea after that. I will agree however, that going at max speed is a bad idea. Slow and steady wins the race, or in this case, has a better chance of not overheating and collapsing on a pile of sand.
Commentary by Keybounce (who has not seen the movie)
Truth in gaming.
There was a game I was playing in, with some friends. (They stayed friends.) We had just gotten a new supplement, and leveled up. So Sarcerok (you might know that name from elsewhere on the internet) decided to get the Mathematics skill. Later, we had to get down a hill as fast as possible. He wanted to use his new skill to optimize the path down to reach the bottom first. The GM said he just teleported to the base with a bamf.
Optimizing a problem in a game with real life skills for determining the best way to reach a goal? Absolutely normal. You should see the number of times I'd move gear around on a computer RPG to maximize the party's survivability - or how much it turned out to matter when in a (I think it was) FF7 battle with the "stoplight" guy, I was down to only a single party member left (took me too long to figure out what his rules were and how the lights worked - if I had, three party members could have kept him in check, and one do damage, but by the time I figured it out I was down to only two left, and was down to one at the end). I think I was one round of combat away from dying when I finally got him.
So ultra optimization? Seen it, done it. Perfect truth in gaming.
GM: Okay, back to Finn. You’ve been slogging across the hot sand for what seems like forever.
Finn: Water... must have... water...
GM: You crest a dune... and see a settlement on the plain below. Oh, and take another Fatigue point.
Finn: I head down as fast as I can!
Rey: No, don’t do that!
Finn: But I want to get there as soon as possible.
Rey: Without collapsing! Here’s the optimal solution: Walk 500 metres nor-nor-west at your normal Move, roll 800 metres nor-east down the hill at 0.75 Move, then head nor-nor-west the rest of the way at 1.5 times Move - which will also help shake the sand off.
Rey: If you go straight at max speed you’ll accumulate more Fatigue per vectored distance.
Finn: How do you...?
Rey: It’s a simple convex optimisation problem.
Finn: Why would anyone do that to decide a game action?
Rey: Because it’s fun!