This is a structure to replicate the undermining of fortifications and which can be built by the miner.
It confers an aura that places additional damage towards structures/buildings, but with speed debuffs like the trench. An example of the additional damage would be 5 damage (with or without bypass armor) with the anti-building bonuses of the swordsman.
With the destruction of the tunnel, the units inside will be destroyed.
Siege tunnel
Re: Siege tunnel
With this avenue of attack, structures can also be additionally strengthened against general means of assault, which can better reflect their strength in medieval sieges.
Re: Siege tunnel
It's problematic.
Such tunnels shouldn't host cavalry or machines, so for them - they can only pass through them, but not stand on them.
Under specific circumstances (a whole field filled with such tunnels) - they would be impassable barrier then.
Such tunnels by simple logic - exist in separate layer of battlefield - underground, so they need to allow free passage for everything not using them.
But the engine doesn't use multiple layers, that units move on.
On flavour side - medieval tunnels were extremely small and rather short, because there were no convenient materials cheap enough to use for strengthening the tunnels.
Mining was one of the most dangerous things to do and the same was true for doing siege tunnels.
Often slaves, prisoners or lowest class were send to actually dig.
And only few men at max for a tunnel. Often only 1.
A whole unit of army wouldn't ever go through underground tunnels. Even if we spoke about foot units - we have to remember, that depending on interpretation and scale used on exact map - it can be viewed as a group numbering 5 - 400 men. Or 1 in some campaigns, but I dislike such interpretation.
Anyway - sending such number with whole equipment would take ages to through such tunnels and they could collapse any time.
So even quickly trained army men would be wasted to send too many like that. The pricier the training and equipment - the more of a waste such danger would posses.
Mercs or knights would never risk like that.
Additionally - such tunnels were most often supposed to be quickly collapsed, making structures over them less stable or even breaking them down to certain level.
So for all intends and purposes - there doesn't really need to exist in-game representation of siege tunnels.
Rather just as an ability or something.
But there is already classic medium infantry bonuses against structures, which can only be explained as them actually having some capability of siege warfare.
So imho - miner (and possibly worker) unit could just get some sort of ability (or simply big bonus damage) against structures.
Such tunnels shouldn't host cavalry or machines, so for them - they can only pass through them, but not stand on them.
Under specific circumstances (a whole field filled with such tunnels) - they would be impassable barrier then.
Such tunnels by simple logic - exist in separate layer of battlefield - underground, so they need to allow free passage for everything not using them.
But the engine doesn't use multiple layers, that units move on.
On flavour side - medieval tunnels were extremely small and rather short, because there were no convenient materials cheap enough to use for strengthening the tunnels.
Mining was one of the most dangerous things to do and the same was true for doing siege tunnels.
Often slaves, prisoners or lowest class were send to actually dig.
And only few men at max for a tunnel. Often only 1.
A whole unit of army wouldn't ever go through underground tunnels. Even if we spoke about foot units - we have to remember, that depending on interpretation and scale used on exact map - it can be viewed as a group numbering 5 - 400 men. Or 1 in some campaigns, but I dislike such interpretation.
Anyway - sending such number with whole equipment would take ages to through such tunnels and they could collapse any time.
So even quickly trained army men would be wasted to send too many like that. The pricier the training and equipment - the more of a waste such danger would posses.
Mercs or knights would never risk like that.
Additionally - such tunnels were most often supposed to be quickly collapsed, making structures over them less stable or even breaking them down to certain level.
So for all intends and purposes - there doesn't really need to exist in-game representation of siege tunnels.
Rather just as an ability or something.
But there is already classic medium infantry bonuses against structures, which can only be explained as them actually having some capability of siege warfare.
So imho - miner (and possibly worker) unit could just get some sort of ability (or simply big bonus damage) against structures.
Age of Strategy design leader