Editing Total War: Warhammer/Tactics (section)

===Subterranean Battles===
Various races (Skaven, Beastmen, Dwarfs and Wood Elves, for example) have alternate movement stances that allow them to ignore otherwise impassable terrain and slip past enemy armies that may be blocking your path forward. The Dwarves and Greenskins had the ability first, and they do it by traveling underground hence why even if Wood Elves and Beastmen don't dig, it's called 'subterranean'. However, enemy armies have a chance to intercept armies moving near/across them in that stance in a battle not terribly dissimilar from an Ambush battle. Like an Ambush battle, the tunneling army is at your mercy; they cannot retreat from an interception. Most tunneling armies will be totally wiped if they are intercepted and are defeated, but some, like the Beastmen and Wood Elves, can still regroup after being defeated. Unlike Ambush battles, armies will deploy normally and neither of them will have any notable tactical advantages in deployment options over the intercepted. You can decline an interception if it is your best interest (say, your army is too weakened to fight or you need to conserve your strength for a more opportune target... which is ''real'' unlikely all things considered) and allow them to go forth unmolested. But this section assumes you do the correct thing and intercept underway/worldroot traversing armies.

The battlefield itself is substantially more constrained over a regular field; a long narrow tunnel/path will typically make up the zone of combat, putting units that rely on maneuverability at a notable disadvantage. Terrain usually favors the defender, with dwarf and skaven maps having almost no cover at all, allowing their gunlines and artillery to fire with impunity and being very hard to flank. On the other hand beastman maps are entirely forested, making artillery useless and ranged attacks easily blocked.