I'm having my bad guys go on the offensive by hiring an assassin to go after the players. My players don't suspect it yet, and I want to have the bad guys be competent but also have the PC's get a fair shake.
With a Classed assassin, Level 4 maybe? they get a very good shot of assassinating a character if they get surprise.
To be fair to the players, in a city setting, should they always get a surprise roll even if the assassin is disguised, or the PC's are drunk, etc?
If I were the player I'd be pissed if the DM told me "hey I rolled really well, so your wizard died, sword in the back", but at the same time, I think a credible threat, a really sinister assassin, should have that high chance.
Should I always give the PC's a roll?
The other thought I had was to have the assassin kill a henchmen. That way its personal, effectively dramatic, and doesn't take player agency away.
Have you guys had the bad guys go on the offensive in a city setting before? When the PC's weren't ready for it? How did you handle it?
Killing a henchman is a great idea. If I have assassins go after player characters, I usually place the assassins at a level where they have about 25% chance. Then I notify the players what is happening and let the players roll that assassination chance.