Hidden units: Invisible to AI too?

**Servius** · 08-29-2009, 03:58

I'd love to get a dev's thoughts on this, but who knows how often they check the threads here. So, short of that, I'd love to hear anecdotal reports if you have any. Here's the question:

In previous TW games, on the battle map, you could hide your units in the woods, but the AI knew they were there. My most vivid memories were back during MTW, where if you hid a unit in the woods, the AI would send one cavalry unit at a walking pace right for it. Once the hidden unit's cover was blown, the rest of the AI force would move up.

I can't personally recall such obvious evidence that the AI knows where hidden units are from RTW or M2TW (my memory of both games is pretty fuzzy), and I can't recall having seen anything that obvious in ETW. ETW also added a lot more units with hiding abilities. Some units (like Rangers) can apparently move unseen on the campaign map, but are seen when they move on the battle map. Other units (like Native American Bowman) can move and stay hidden on the battle map, so long as they walk and don't run. They can even fire their bows and remain hidden. Then there are many units who can hide in just woods, or woods and tall grass, or woods, tall grass, and short grass, etc.

With all this potential for strategic (camp map) and tactical (battle map) trickery and cleverness, I want to know if it actually works against the AI, or just against human players.

>>>>>>>>>>>>>>

Also, in a related but slightly different area, it seems that Generals have no ability to hide. I get the reason for that, but what it means is that you can't have a fully-hidden force on the camp map unless that force lacks a general to lead them. If this is true, then that means that the 'paths less trodden' ability simply keeps players (and maybe the AI) from knowing the full size of stacks on the camp map. Because of the general, they'll know where the stack is, but because of 'paths less trodden' they might not know the full size of the stack. Is this a correct understanding?

**Prussian to the Iron** · 08-29-2009, 16:50

in m2, RTW, and ETW, i have never once had a hidden unit that was not attacked by the enemy (on the battlemap, i dont know about campaign map), despite being perfectly camoflauged, unless I was playing on easy difficulty for campaign and battle.

so basically: no. units on the battle-map are not invisible to enemy a.i.

**FactionHeir** · 08-29-2009, 21:17

They know where they are hidden in every title.

In ETW, they just walk really slowly up to your hidden units if they are ranged and then run as soon as they get within your firing range, even if your units are not on fire at will. In that, the AI will make a point of going after your hidden units first in many cases.

**Dreadnought2** · 08-30-2009, 13:53

I beg to differ...

I've had units that I've moved forward into woods and the AI's army has moved to counter the move...my unit stops in the woods but takes a few seconds to 'hide' so the enemy keep advancing...then my unit becomes hidden and the AI troops immediately lose interest and head off towards my non-hidden units. If they knew where hidden units are, why would this happen?

I've used this with good affect in fort attacks where there are woods between the starting point for my forces and the fort. I've run some of my infantry into the woods on the flank of the fort and the enemy relocate on the walls to counter the move, then my troops 'cloak' in the trees giving them time to recover for the final move towards the fort and the AI troops happily turn around and head back to look at my other troops cheerfully demonstrating in front of the fort.

I've also seen some very good ambushes by light infantry and similar units. Going by the AI's reaction to being caught in the open by these troops, the AI simply had not known they were there.

Cheers,
Dreadnought2

**Slaists** · 08-30-2009, 15:43

Originally Posted by FactionHeir

They know where they are hidden in every title.

In ETW, they just walk really slowly up to your hidden units if they are ranged and then run as soon as they get within your firing range, even if your units are not on fire at will. In that, the AI will make a point of going after your hidden units first in many cases.

Hmm. My experience is quite different. Sometimes I even use a "trap" whereby I have 4 native american musketmen hiding in long grass or scrub away from my main body of my troops. I'd run a single cavalry unit towards the enemy baiting their cavalry out. Running the bait cavalry back through the hidden musketmen would result in total annihilation for the AI cavalry, so, it seemed, the AI could not see the hidden units.

However, I have to note that this worked better before the 1.3.1 patch. CA has explicitly stated the the 'spot view' range has been increased for many units (especially scout types and cavalry). So, post 1.3.1, your hidden units are spotted at farther distance. As a result, one needs to pay closer attention to the terrain where the units are hidden. The 'spotting' distance has terrain adjustments. It's hardest to spot units if they hide in forest; a bit less hard if they hide in bush/long grass, etc., but easiest if they hide in plain view (some unit types can do that).

As to that walking/running part. I believe, what's involved is the AI walking towards its target (as they usually do); spotting your hidden units at the new increased 'spotting range' and then closing in for the kill.

**Prussian to the Iron** · 08-30-2009, 21:35

could it perhaps be that, at least in E:TW, certain units (like native indian units) are invisible as they should be, whereas others (like pandours, rangers) are only hidden from the A.I. at easier difficulty levels?

if that's not it, then I cannot explain why some people have the A.I. seeing their supposedly 'hidden' units, whereas others have them behave like they should (at least in regards to hidden units)

**Dreadnought2** · 08-30-2009, 23:39

It must be just the fog of war...
Sometimes it works, sometimes it doesn't - just like real life!
Cheers,
Dreadnought2

**Slaists** · 08-31-2009, 14:30

Originally Posted by Prussian Iron

could it perhaps be that, at least in E:TW, certain units (like native indian units) are invisible as they should be, whereas others (like pandours, rangers) are only hidden from the A.I. at easier difficulty levels?

if that's not it, then I cannot explain why some people have the A.I. seeing their supposedly 'hidden' units, whereas others have them behave like they should (at least in regards to hidden units)

I suspect, people are confusing the AI really seeing the hidden units with the AI going for spots that it would go to anyway, even without knowing there were hidden units. For instance, players are likely to hide units in trees on the flanks of their line. However, the AI is very likely to go for the flanks of the player's position by default. So, it might seem, the AI "knows" there is something to go for in the trees. However, the truth of the matter in this case would be that the AI was just executing the standard flanking maneuver and started running towards the hidden units after its cavalry spotted them.