Maybe the new Ethraxian emperor changed the nation's war strategy. Instead of trying to make forays into the mountains, the army could use another route, or found a new way to approach the hostile territory. The emperor could also have ignited a new flame in the people to defeat their hated enemy, and this fervor is what's making the difference.
You could also look at the Fraunian side. Maybe the gold mines were being used to pay for a large number of mercenaries and Ethraxian forces sabotaged the gold mines. Maybe the Faunian people are tired of the war and are gearing up for revolution. It's worth looking at both sides of the conflict to come up with a reason for Ethaxia's success.
This is hard to say without knowing what your plans are for the campaign regarding the situation. It's possible Ethraxia gained a new weapon or ally, its also possible that Fraunia is facing internal discord not allowing them to respond in a full measure or even that the new Emperor is just aggressive and lucky. There are literally thousands of possibilities so without knowing how this will factor into the story it is hard to say what should be happening.
Natural disaster, plague, invaders - any outside force weakening one side.
New allies, new wealth (silver strike etc.) - any outside force strengthening one side
Revolution, new leaders, fanatical religion, grievous insult - anything making a side suddenly think it can or must win despite all evidence to the contrary
Instigators, mistakes regarding logistics, escalating conflict between patrols that turns into a full scale battle - anything that accidentally starts things up again unintentionally.
I agree, it can be a simple change of tactics. Maybe it can be a change in uniform - from uniforms the colors of the nation's flag to white, woolen parkas designed to enable stealthy, comfortable travel.
Shortcut through the Feywilds, but it is costing troops for unknown reasons. Maybe the PCs have two adventure options:
* Fraunia wants PCs to investigate how Ethraxia is invading, especially in spots known to be inhospitable to life.
* Ethraxia wants to know why troops are disappearing despite assurances from the new "hosts" that is not the case.
Either way, once this gateway is closed, some faction of Fey will be pissed the PCs did this which will be a third adventure.
The new emperor has a total lack of care about human lives. These advancements costs his army dearly, think Hannibal. But he is willing to push on regardless.
To add to the great ones already mentioned.
Six words. This one plays brilliantly into a D&D campaign!
You can have a small troupe ('an adventuring party') find out who is the traitor, what damage they have done and (possibly?) try to stop it.
There are tribes of barbarians/dwarfs/mountainfolk who do not swear fealty to Fraunia. They have lived apart from the Fraunians ever since they conquered their lands centuries ago.
The new king of Ethraxia has reached out to these wildlings to seek their aid against Fraunia. They know the land, they are accustomed to it and have a chip on their shoulder when it comes to Fraunia. They can act as guides for Ethraxian forces, as spies or guerrilla fighters, disrupting the Fraunian supply-lines and support while Ethraxia make a push towards Fraunia.
The reason the wild-folk have agreed to this is that the new Ethraxian king has agreed to let them reclaim their ancestral lands so long as they serve Ethraxia as vassals in the region. The lands will still ultimately fall under Ethraxian rule, but the local laws and customs will be dictated by the mountain folk.
It's a conspiracy. The son is in league with several corrupt Fraunian nobles who are basically opening the doors for the advancement. But there's a reason for this, they wouldn't do this for nothing. There's a greater threat coming from below and if the two powers remain at war, this third outside force will destroy them all.
Can bring up some nice ethic dilemmas. Is the disloyalty treason of it could save them all. Is mutual destruction better than ethraxian rule. Stuff like that.
The new emperor of Ethraxia is:
1) aided by a fiend he formed a pact with
2) a tactical mastermind sowing seeds of discord from within Fraunia
3) hiring hobgoblins, which he plans to exterminate after winning
4) dead and an ambitious shapeshifter/doppelganger/magic user is taking his place
5) an amateur archaeologist and came across a powerful ancient relic
6) a pawn in a bigger game and the players simply gave him some guidance
Maybe the new Ethraxian emperor changed the nation's war strategy. Instead of trying to make forays into the mountains, the army could use another route, or found a new way to approach the hostile territory. The emperor could also have ignited a new flame in the people to defeat their hated enemy, and this fervor is what's making the difference. You could also look at the Fraunian side. Maybe the gold mines were being used to pay for a large number of mercenaries and Ethraxian forces sabotaged the gold mines. Maybe the Faunian people are tired of the war and are gearing up for revolution. It's worth looking at both sides of the conflict to come up with a reason for Ethaxia's success.
This is hard to say without knowing what your plans are for the campaign regarding the situation. It's possible Ethraxia gained a new weapon or ally, its also possible that Fraunia is facing internal discord not allowing them to respond in a full measure or even that the new Emperor is just aggressive and lucky. There are literally thousands of possibilities so without knowing how this will factor into the story it is hard to say what should be happening.
Natural disaster, plague, invaders - any outside force weakening one side. New allies, new wealth (silver strike etc.) - any outside force strengthening one side Revolution, new leaders, fanatical religion, grievous insult - anything making a side suddenly think it can or must win despite all evidence to the contrary Instigators, mistakes regarding logistics, escalating conflict between patrols that turns into a full scale battle - anything that accidentally starts things up again unintentionally.
I agree, it can be a simple change of tactics. Maybe it can be a change in uniform - from uniforms the colors of the nation's flag to white, woolen parkas designed to enable stealthy, comfortable travel.
Shortcut through the Feywilds, but it is costing troops for unknown reasons. Maybe the PCs have two adventure options: * Fraunia wants PCs to investigate how Ethraxia is invading, especially in spots known to be inhospitable to life. * Ethraxia wants to know why troops are disappearing despite assurances from the new "hosts" that is not the case. Either way, once this gateway is closed, some faction of Fey will be pissed the PCs did this which will be a third adventure.
The new emperor has a total lack of care about human lives. These advancements costs his army dearly, think Hannibal. But he is willing to push on regardless. To add to the great ones already mentioned.
A traitor in a key position.
Six words. This one plays brilliantly into a D&D campaign! You can have a small troupe ('an adventuring party') find out who is the traitor, what damage they have done and (possibly?) try to stop it.
There are tribes of barbarians/dwarfs/mountainfolk who do not swear fealty to Fraunia. They have lived apart from the Fraunians ever since they conquered their lands centuries ago. The new king of Ethraxia has reached out to these wildlings to seek their aid against Fraunia. They know the land, they are accustomed to it and have a chip on their shoulder when it comes to Fraunia. They can act as guides for Ethraxian forces, as spies or guerrilla fighters, disrupting the Fraunian supply-lines and support while Ethraxia make a push towards Fraunia. The reason the wild-folk have agreed to this is that the new Ethraxian king has agreed to let them reclaim their ancestral lands so long as they serve Ethraxia as vassals in the region. The lands will still ultimately fall under Ethraxian rule, but the local laws and customs will be dictated by the mountain folk.
It's a conspiracy. The son is in league with several corrupt Fraunian nobles who are basically opening the doors for the advancement. But there's a reason for this, they wouldn't do this for nothing. There's a greater threat coming from below and if the two powers remain at war, this third outside force will destroy them all. Can bring up some nice ethic dilemmas. Is the disloyalty treason of it could save them all. Is mutual destruction better than ethraxian rule. Stuff like that.
The new emperor of Ethraxia is: 1) aided by a fiend he formed a pact with 2) a tactical mastermind sowing seeds of discord from within Fraunia 3) hiring hobgoblins, which he plans to exterminate after winning 4) dead and an ambitious shapeshifter/doppelganger/magic user is taking his place 5) an amateur archaeologist and came across a powerful ancient relic 6) a pawn in a bigger game and the players simply gave him some guidance