I need some help with designing an encounter. (I'm new at this)
What I've got is the party enters an old library which a small gang of thieves are using for a hideout, they thieves have made off with some jewels the night before and have just gotten back from their thieving.
I was going to have their leader sitting in the main room inspecting the loot and the other thieves upstairs asleep, if the party are sneaky or clever they can kill the upstairs ones first then work on the boss, or kill the boss first, whatever they want.
But if they do what i think they'll do they'll rush in and attack the main guy which will allow the guys on balcony's to shoot down and probably destroy them.
Now i was gonna have four 1/2 CR thieves on the balconies and a 2 CR leader, the group are only four level one PCs in one of their first games. It's also just a one shot so dying isn't so bad.
I was thinking of making the thieves fatigued but i'm not sure how the fight would go if they rush in. Is it too much or should I use this as an example for them not to be stupid?