natanyeelarruda::Eu sendo o defensor posso recuar para qualquer área adjacente vazia? Até as áreas com castelos/fortalezas?

Qualquer área, não. 

Soldados e cavaleiros não podem recuar para porto e mar, em qualquer hipótese 

Navios não podem recuar para áreas de terra,  em qualquer hipótese 

A área adjacente vazia não pode conter unidades e ou tokens de poder dos adversários 

A área adjacente vazia não pode ser a mesma de onde o atacante partiu

As catapultas não recuam em hipótese alguma

Ainda que seja uma área vazia adjacente válida,  deverá ser respeitado imediatamente a quantidade de unidades por território permitida pelos suprimentos, eliminando as unidades que passarem da quantidade prevista 

3. Retreats and Routing

After suffering casualties, the losing army must retreat from  the embattled area (supporting units do not retreat.)
If the attacker lost the combat, his surviving units must retreat  back to the area from which they marched.

 If the defender lost the combat, his surviving units must retreat  using the following rules:

ɇ The retreating units must retreat to one empty adjacent
area (i.e., one containing no enemy units or enemy Power 
tokens) or to a friendly area (i.e., one containing friendly 
units, and/or a friendly Power token). 

ɇ The retreating units must retreat to the same area. 

ɇ The retreating units may never retreat to the area the 
attacking units marched from, even if it is empty.

ɇ A player may not retreat his defending units to an area 
containing friendly units if this would cause him to 
exceed his Supply limit. If a player’s only option is to 
retreat to such an area, he must first destroy as many 
retreating units as necessary to be compliant with his 
Supply limit after retreating to the area. After taking such 
losses, he may retreat the remaining units.

ɇ If there is no legal area in which to retreat, all retreating 
units are destroyed. 

ɇ Footmen or Knight units may not retreat to a sea area or a  port. Ship units may never retreat to a land area.
After retreating, all retreated units are placed on their sides to  signify they are now routed. Routed units provide no Combat  Strength, but still count towards a player’s supply limit. If a routed  unit is forced to retreat, it is instead destroyed. Routed units may  never be chosen as casualties in combat and may not move, even if  a March Order token is resolved in their new area. 

Other Retreat Rules

ɇ A player is allowed to use ship transport to retreat his 
units (see page 23 for ship transport rules). 

ɇ Siege Engine units cannot retreat. If a Siege Engine unit is 
forced to retreat, it is instead destroyed.