I agree. The spell would make the cultist believe the leader would want the players to be allowed to pass. The plot point could still have been saved less clumsily and without completely penalising the players by having another cultist realise what had happened and stab the suggested cultist in the back.
"These aren't the droids you are looking for".
You think Vader gave those troopers a medal when they reported in?
I imagine that shortly after Luke drove off the squads conversation went something like this:
"Sgt, why'd you let those two go without seeing their IDs?"
"Yeah boss, that one droid even had blue trim. Aren't we looking for a droid with blue trim?"
(Sgt realizing what's going to happen when they get back to the Star Destroyer) "Oh Sh***!"
And inspires a starting point for a future SW game.
Character creation = Everyone roll up a Storm Trooper. You're all part of the same squad.
Play begins shortly after you realize that you've allowed Luke & Obi-Wan to drive through your check point.
What do you do?
So why allow the save in the first place?
That is no reasonable request. It is an order without any reason given.I had one spell left, so I cast suggestion on him to tell his squad to step aside and let us pass unaccosted.
I think the DM's ruling was correct. Your character didn't know, and had no way of knowing, that allowing you to get away was an explicitly deadly action for the cultist. However, that doesn't change the fact that that was an unreasonable request. That's just how reality works. That is to say, this was unfair in the same way that real life is unfair. That's a feature, not a bug! Sometimes you get tripped up by things you don't know.
You had no way to know that sword was cursed. You had no way to know that floor was an illusion. You had no way to know the sheriff was a Doppelganger. You had no way to know that the cultists were instructed to return with the treasure or face execution.
Most likely just because the DM didn't think beyond, "a spell was cast that grants a save; let's roll the save before thinking beyond that." However, if you think deeper, it was actually most correct to do it that way! Since the casting character has no idea that their suggestion was unreasonable or why, telling the PC that the NPC doesn't need to roll is giving out metagame information. It's better to just roll.
Indeed, this is a perfect example of when the DM should be rolling behind a screen. Then the DM can say, "The spell doesn't appear to have had any effect." It doesn't matter why there was no effect. The PC doesn't get to know that. They might be immune to charm, or they might be illusory creatures, or they might not understand the language the PC spoke, or they might not have been able to hear the PCs, or they might've made their save, or it might be unreasonable, etc. There are lots of ways for the spell to do nothing. Why should the DM tell the PCs which one it was?
That's basically the baseline I give for it being a spell - they are basically evaluating it just for itself, not including at all that they don't know you for anything or that the context is sketchy.The spell is missing a critical feature. It should say "if they were your friend" and they would clear up an enormous amount