I have heard that it is possible to start a sidequest through the use of dungeon boss flags, as was done in Hero of Dreams. First, can someone tell me how you trigger something when a boss is killed, such as warping out of the room in the case of a custom boss? After that, how would you change the strings people say through the flag's use?
Starting Sidequests
Are you saying you want to warp out of the boss room after killing the boss? If that's the case, what you need to do is set the 'enemies to secret' flag, and have a copy of all of the floor tiles you're using, but with a combo such as direct warp or stairs set to the secret tiles. This would change the floor to a warp after beating the boss (although the player would'nt know)
Actually, I would recommend to put all boss room combos on layer 1, and then when the boss is killed, invisible direct warps would trigger on layer 0.
Also if you use any method check 'no secret sound' screen rule so that it makes it more smooth and dosent play the secret SFX
That makes perfect sense. But how can complicated sidequests such as the suit delivering one in Hero of Dreams be started with dungeon boss flags?
Used to be that Boss Flags were your answer. Today, room state carryover secrets are your answer.
Go to Screen->Data (or whatever its called). See that "Room State Carryover" section? Well, whatever screen you specify in that box will have its secrets triggered when the current room's secrets are triggered.
So, have your boss room set to Enemies->Secret. (Might have to set "all secrets are permanent" too). Then set the room state carryover to a room with an otherwise locked door, stubborn npc, or something else. Set the secrets on that second screen to open up a path when the secrets are triggered. Viola.
I have no idea what that room carryover thing is. Do you use a beta version?
Yes. I think it was first done in early 2.11 betas i think