This roaming tutorial will make all monsters move towards one common goalentity.

Step 1.

Type these prototypes at the very top of world.qc:

void() Arc_Figgin;
void() S_Figgin;
void() T_Figgin;

/*
=================================================================================

FIGGIN

=================================================================================
*/

void() Arc_Figgin =
{
	local entity figgin;				//Make an entity called "figgin"
	
	figgin = spawn();					//Spawn the figgin
	figgin.classname = "figgin";			//It's a figgin
	figgin.movetype = MOVETYPE_NONE;		//It doesn't move
	figgin.solid = SOLID_BBOX;			//It can be touched
	setsize(figgin, '-1 -1 -1', '1 1 1');	//It's size is '2 2 2'
	
	figgin.origin_x = (0.5 - random())* 2 * 5000;	//It's origin is randomized
	figgin.origin_y = (0.5 - random())* 2 * 5000;
	figgin.origin_z = (0.5 - random())* 2 * 5000;
	
	while((pointcontents(figgin.origin) != CONTENT_EMPTY) && (figgin.aflag < 75))
	{
		//If the pointcontents of the figgin's origin is not empty, reset the figgin
		//To a more suitable space. If no space can be found within 75 loops,
		//Leave it where it last was placed.
		figgin.origin_x = (0.5 - random())* 2 * 5000;
		figgin.origin_y = (0.5 - random())* 2 * 5000;
		figgin.origin_z = (0.5 - random())* 2 * 5000;
		
		figgin.aflag = figgin.aflag + 1;
	}
	
	figgin.nextthink = time + 0.1;		//.1 seconds from now
	figgin.think = S_Figgin;			//You will do something else
	
	figgin.touch = T_Figgin;			//If touched...
};

void() S_Figgin =
{
	local entity flick;				//Declare an entity to be used for the
								//findradius function
	
	flick = findradius(self.origin, 10000);
	
	while(flick)
	{
		if(flick.flags & FL_MONSTER)		//If flick is a monster
		{
			if(flick.health > 0)		//If he has health
			{
				if(flick.search_time < time)	//If he aint looking for the player
				{
					if((flick.enemy == world) || (flick.enemy == self))	//If he doesn't have an enemy
					{
						flick.goalentity = self;	//Your target is a figgin.
						flick.nextthink = time + 0.1;	//In .1 seconds
						flick.think = flick.th_walk;	//You will walk
					}
				}
			}
		}
	flick = flick.chain;		//Next entity in line
	}
	
	self.aflag = 0;	//Reset the loop counter
	
	self.nextthink = time + 3 + random() * 3;	//In 3-6 seconds
	self.think = T_Figgin;				//Act as if it's been touched
};

void() T_Figgin =
{
	//Random origin
	self.origin_x = (0.5 - random())* 2 * 5000;
	self.origin_y = (0.5 - random())* 2 * 5000;
	self.origin_z = (0.5 - random())* 2 * 5000;
	
	while((pointcontents(self.origin) != CONTENT_EMPTY) && (self.aflag < 75))
	{
		//Check for where it is
		self.origin_x = (0.5 - random())* 2 * 5000;
		self.origin_y = (0.5 - random())* 2 * 5000;
		self.origin_z = (0.5 - random())* 2 * 5000;
	
		self.aflag = self.aflag + 1;
	}

	self.nextthink = time + 0.1;	//Wash rinse
	self.think = S_Figgin;		//Repeat
};

Arc_Figgin();

I hope this tutorial works (I used it in smod1, but something may have broken). If not, Knock me one at sestze@yahoo.com

Lastly: A figgin is a type of fruitcake, for those who gandered as to what the hell it meant.