How do I make an actor spawn after some time has passed since the map has been loaded?

34 minutes ago, Gianluco said:

I want to make a boss that spawns after some time (It'd be better if it were random), how do I do it? I was also thinking about using multiple spawners around the map and, after one spawns the boss, the other ones are deactivated. 

The best way without scripting is make a monster closet with teleporter linedefs on the back of a raised floor. Raise the floor like a 1000 units, and have the linedef that triggers the floor to lower at a slow speed. You can raise the floor beyond the ceiling to increase the time. Use a speed of 4 units or thereabouts to lower the floor. Playtest to get the right height for the time delay required.

Edit the front linedef of the floor with a  Monster Walks Over functions .... hopefully you're using UDMF, if not it's all still possible like this.

10 hours ago, NoOne said:

The best way without scripting is make a monster closet with teleporter linedefs on the back of a raised floor. Raise the floor like a 1000 units, and have the linedef that triggers the floor to lower at a slow speed. You can raise the floor beyond the ceiling to increase the time. Use a speed of 4 units or thereabouts to lower the floor. Playtest to get the right height for the time delay required.

 

Edit the front linedef of the floor with a  Monster Walks Over functions .... hopefully you're using UDMF, if not it's all still possible like this.

 

That makes sense. By coincidence and for different reasons I built a similar mechanism into a map.  

CLASS BOSSSPAWNER : BrainStem
{
	Default
	{
	Scale 0.55;
	Radius 20;
	Height 25;
	}
	States
	{
	Spawn:
	TNT1 A 1;
	TNT1 A random(106, 1920);
	TNT1 A 1 A_SpawnItemEx ("BOSS",0,0,0,0,0,0,0,SXF_NOCHECKPOSITION,0);
	Stop;
	}
}

Gianluco, you could put code like this into your zscript lump, give it a doomednum in your mapinfo, and then place it in an inaccessible room on your map. replace "BOSS" with your boss monster and then code the boss to wander around when it is spawned. surround the boss spawner with a ring of teleporting line defs with different destination sectors, adjust the random tics range to taste, and then you get a boss that arrives at a random place after a random time in your map.