When i first read about the barbarian preference for the NW/SE axis i was a little confused because i always seemed to have exceptions. While working on a newer The Ancient Mediterranean Mod (soon to be available) i figured out part of the barbarian problem.
Adding NoAIPatrol=1 to your ini file in an attempt to speed the turns up by reducing the AI movement of units affects the barbarians as well. With this flag set, they just fortify where they are and won't move unless an enemy unit is on the NW/SE axis somewhere on the map.
By just changing it to NoAIPatrol=0 they wander around more. They still have the preference for the NW/SE axis but because they move around, they are also more likely to get on it.
The Barbarians will also attack off the prefered axis ocassionally. I have not tested enough to determine if it is the ini file flag or the activity setting and don't plan on doing so. What I do know is that with NoAIPatrol=0 *AND* Raging barbarians, they will attack off axis. They are still predictable and won't always attack in other directions but it does make them more interesting, less predictable and thus more dangerous.
I do have an unproven theory on when they will attack off axis: When the barbarians want to go somewhere, they almost always choose the higher defensive terrain to move to first. If you have a unit on the off axis tile they would prefer to move to they will attack.
EDIT: Justus II did some testing and posted the results here:
http://forums.civfanatics.com/showpost.php?p=2217331&postcount=22
Edit: SirPleb has posted a comprehensive list of observed barbarian behavior:
http://forums.civfanatics.com/showpost.php?p=2221471&postcount=37
Edit: ainwood has made a small utility for those players who are uncomfortable modifying the ini file: http://gotm.civfanatics.net/civassist/BarbFixer.zip
To summarize what we know so far about how the NoAIParol flag affects barbarians (and now playable civs thanks to Justus II):
a) Absence of NoAIPatrol flag is the same as NoAIPatrol=1 for C3C only. PTW defaults to =0, C3C defaults to =1.
b) NoAIPatrol=0 in your conquests.ini file is the only way to turn patrolling back on in C3C for all AI units including barbarians. This restores the barbarian activity close to PTW expected behaivior.
c) The barbarians still have the preference for the NW/SE axis and remain somewhat predictable with AI patrolling allowed BUT they WILL attack off axis. You can still lead them around by moving units on and off the axis and predict which tile they will move to if one tile has a higher defensive bonus than the others.
d) The ini file is read only when C3C is first started. Therefore, if you want to change the flag mid game, you must exit the game and restart it.
(I always played with =0 assuming it was the same as no flag and is why i noticed discrepancies)
Adding NoAIPatrol=1 to your ini file in an attempt to speed the turns up by reducing the AI movement of units affects the barbarians as well. With this flag set, they just fortify where they are and won't move unless an enemy unit is on the NW/SE axis somewhere on the map.
By just changing it to NoAIPatrol=0 they wander around more. They still have the preference for the NW/SE axis but because they move around, they are also more likely to get on it.
The Barbarians will also attack off the prefered axis ocassionally. I have not tested enough to determine if it is the ini file flag or the activity setting and don't plan on doing so. What I do know is that with NoAIPatrol=0 *AND* Raging barbarians, they will attack off axis. They are still predictable and won't always attack in other directions but it does make them more interesting, less predictable and thus more dangerous.
I do have an unproven theory on when they will attack off axis: When the barbarians want to go somewhere, they almost always choose the higher defensive terrain to move to first. If you have a unit on the off axis tile they would prefer to move to they will attack.
EDIT: Justus II did some testing and posted the results here:
http://forums.civfanatics.com/showpost.php?p=2217331&postcount=22
Edit: SirPleb has posted a comprehensive list of observed barbarian behavior:
http://forums.civfanatics.com/showpost.php?p=2221471&postcount=37
Edit: ainwood has made a small utility for those players who are uncomfortable modifying the ini file: http://gotm.civfanatics.net/civassist/BarbFixer.zip
To summarize what we know so far about how the NoAIParol flag affects barbarians (and now playable civs thanks to Justus II):
a) Absence of NoAIPatrol flag is the same as NoAIPatrol=1 for C3C only. PTW defaults to =0, C3C defaults to =1.
b) NoAIPatrol=0 in your conquests.ini file is the only way to turn patrolling back on in C3C for all AI units including barbarians. This restores the barbarian activity close to PTW expected behaivior.
c) The barbarians still have the preference for the NW/SE axis and remain somewhat predictable with AI patrolling allowed BUT they WILL attack off axis. You can still lead them around by moving units on and off the axis and predict which tile they will move to if one tile has a higher defensive bonus than the others.
d) The ini file is read only when C3C is first started. Therefore, if you want to change the flag mid game, you must exit the game and restart it.
(I always played with =0 assuming it was the same as no flag and is why i noticed discrepancies)