This sounds like a fantastic predicament! Here is what I would do, take it
for what it is worth:).
1. I would make it VERY unlikely that the PCs could rule a goblin
nation/province. If the PCs decide that they will pillage the provinces down
to nothing.... this means a lot of upset goblins.
2. Unlike humans, goblins cannot just migrate to other kingdoms. I
would assume that they are fairly trapped.... thus the pillaging might reduce
the provinces holdings, and garner the PCs some gold... but I would have the
goblins go into a rebellion of sorts, and create levies. These levies would
be units of Goblin Irregulars. Being a warlike people anyways, highly mobile,
and fairly cowardly... I would have all the units escort their populace from
the province if it looks like they will be pillaged more than once...reducing
the province immediately (well in a domain turn) to 0. These retreating units
would look for a province they could go to for protection....for goblins their
strength is in sheer numbers.
3. Have as the goblins retreat to a safer province (any surrounding
province that you think is suitable) and have a goblin warlord rise out of the
masses, and be elected Khan (or whatever).
4. As far as the numbers of units.... If you had a province of goblins
lvl 4 I would say it immediately levies all its members for the "flight" away
from the naaaaasty hummmanses. That to me means 4+3+2+1 = 10 units of goblin
irregulars in that province. Being a warlike race etc... I would be inclined
to say they could muster more than that... lets another 50% to make 15 units
(this is optional). These units do not require upkeep... they are doing this
for survival and not for pay. They would pillage their own province (slash
and burn) for food, valuables, wood etc, and hunt on the move. I might even
allow a 10% chance or so that a unit mustered becomes other than a core or elite unit of the old goblin warriors...the wounded
or those that routed from previous battles.
5. This may seem a little extreme I know. But basically you are talking
about a fight for survival for the goblins... there are few places they can
migrate. The idea for you should be to give genesis to the "Horde", the "The
Goblin Host" etc. Let the PCs pillage first...once or twice in a province and
then the next time they try.... they find it almost deserted. Streams of
goblins fleeing under the cover of darkness to unite with other tribes.
Rumors of chieftains burying the hatchet...and welcoming their goblin brothers
in defense against a common enemy, should be rampant amongst the rangers and
druids of the area. A common overwhelming enemy logically forces the goblins
to do this. Safety in numbers. Their own kind etc.
6. I would then create (if you want to be really nasty) a self
generating momentum.... At some point, you the DM need to decide, that after
this... the humans have just gone too far.... goblin provinces are slowly
abandoned... as they travel to the safety of their great warlord. After this
point...ceasing to loot/pillage the goblin provinces etc does no good. The
goblins continue to leave... amassing in the great chieftains province.... and
generating The Goblin WarHost.
7. As the WarHost forms.... dispondent goblins and would be chieftains
from all over Cerilia seek out the new warlord, and the promise of battle
glory.... riches, and vengence.
8. The Host at some point needs money and labor to feed its growing
mass. Un defended or lightly provinces of ANY kingdom near the horde become
targeted. They are completely looted/pillaged/burned...and humans hauled away
to be slaves in the trecherous mines that have been created to gain ore for
new weapons. They are used to farm crops, tend livestock, make weapons,
quarry stone and (my goodness raise a citadel for the new warlord). Use the
goblins mobility and cowardly natures to effect. They seldom attack heavily
fortified areas, or large masses of troops. They defend their citidel, but
carry most everything else with them. Use them to totally destroy some
surrounding weakly defended provinces....this will cause the PCs some grief as
other kingdoms blame the rise of the Horde on them...:) Rule One: The Horde
never goes to the PCs, they must come to it and fight on its terrain.... use
the terrain cards in the goblins favor. Forests are great!
9. I would allow the build up to continue for about a year or so (in
Domain Turns). You can get a number of great adventures in during that
time... (See the AD&D adventure "The Silver Key" for example) as PCs try in
vain to stunt the swelling ranks of the horde.... these should have some
effects keeping growth to a minimum that turn, but failure creates the
opposite effects.
10. Create the atmosphere that the goblin problem is slowly but surely
gaining momentum and becoming "out of control" and "unmanageable". Alliances
will be needed to muster the troops to support stopping this problem....
Remember all the while that once the goblin "infestation" becomes very one kingdom is going to risk their entire army to stop it by
themselves.... if they fair poorly, and loose too severly, their kingdom will
become vulnerable not just to the goblins but to surrounding regents. I would
have many of the surrounding regents dismiss the "infestation" as a historical
cycle... that will "die out...or run its course" or just hysteria. Make many
of the other surrounding kingdoms slow to react. Inertia and non-commitment
can be seen as a great source of frustration for the PCs. Treachery IS A
MUST!!!. DO NOT have all the regents who promise to fight in the final
"climactic battle" show up. Or they show up, but decide not to fight (See the
movie Braveheart). Many of these regents will see the possibility of a weak
(PCs realm) as ripe for the picking... especially after the goblins are
severely quelled by the final battle with the PCs. After all the PCs are
responsible for forcing the goblins together like this.... it is thier
problem...mostly? And the Horde is mainly seeking vengence against
11. When the WarHost fianally attacks....the goblins do it IN MASS.
Anyone who studies military history know that Mass is a key tennant to
warfare. When they attack.... have no mercy! The PCs were the catalyst that
started the mess in the first place, and if they are "righteous" they will see
to its end. Attack, Burn, Pillage, Loot, and lay waste to as many of the PCs
provinces as possible. When the horde reaches 1/2 to 1/3 of its attacking
size it retreats back to its original province...the citadel regenerate.
12. Wash, rinse....and REPEAT. News of the goblin sucess triggers
inflows of new recruits from all over Cerilia! The Horde begins to build
again.... By this time the PCs will be building the Great Wall of China to
keep the horde out. War Colleges will spring up in the capital city....
Armorers Guilds, Armories will be in full production. Monuments to fallen
units....and heroes will go up. They will be watching their back against
untrustworthy allies...etc. etc. Most of all... do not bring it weak! This
can be a conflict of legends that will have your PCs saying remember when....
The WarHost of Thurazor... They will grumble all the way.... but if you
build it slow and gain steam as you go along... the hair will stand up on the
backs of their necks when the intelligence reports come in....(mix fact with
fiction)... and list for the exclamations of WHAT? HOW MANY?....and YOU Have
got to be kidding me!!
Sorry this was so long. Just my 2 cents :) No yoyu are not in a bad
position.... The rise of the famed Host of the Goblins awaits. This kind of
gritty campain is what the legends are made have the perfect

Im Out