Do dialogue choices lock you out of anything anywhere?

[Alexios Nikator]

I don't mean the obvious "give money" vs "combat", I mean stuff like talking to Cicero and Cato.

Since there are apparently no good guides for this game (wtf), it's a bit difficult to see whether I've jeopardised my ending because I said the wrong thing to someone at some point. Are there any known important "hidden" choices?..

[=DeadShot=]

1. You are locked out of Crocea Mors if you are not careful enough when you first talk with Cotta in Rome.
2. During the dialog choice during Act 1 main quest smuggler, after defeating Corvinus you have to make a choice that has far reaching consequences.
3. You can or cannot get another rhetorical skill from Cicero at the end of act 1 beginning of act 2. And of course how you talk with Cato and Cicero during the entire game can locked you out of the best ending(the fate of Caeso in a crossing of Rubicon scenario, fate of Calida in general).
4. How you talk can influence who lives and who dies and all this can influence the ending for those factions. And can lock you out of items (for example not killing the druid at the end of End of Aedui quest can lock you out of his crown, but killing the druid is the worst ending for the Aedui), endings.
5. You can get or not get the proconsul if you kill Cleo at the end of act 2 and you're main character is a man. But Cleo alive can testify in the Senate at the end when you put Lurco out.
6. Your reputation with your companion matter, and doing their personal quests matter.
7. So depends how you want to go for the ending , but keeping people alive is better than killing them. Only thing that is not is I believe Vercingetorix, Mithriades, Dumonix(end of Aedui druid).
On the other hand taking Vercingetorix captive is better than killing or setting him free, if you plan to have the maximum number of people testifying in the Senate to condemn Lurco. But is bad for Gaul and Vercingetorix personally for the ending.
Mithriades fate is decided at 2. at my decision and can lock you out of extremely good crown. Also affect the ending for Pontus.

[Kirara]

Nope, there are none. Endings will be decided by one single decision at certain point of story. Two of them are mutually exclusive, while others can be achieved from both of 2 branches. Of course, depending of what you did, there might be some variations to them as well. Same goes for main story. Some choices will affect how certain events unfold, but none of it will ever lock you out of any ending.

[OutlawedDrifter]

Originally posted by =DeadShot=:

6. Your reputation with your companion matter, and doing their personal quests matter.

By reputation do you mean their morale?

[=DeadShot=]

I think so. Also in general, I think what choices you take and quest you do will matter in the end (like Damsel in Distress) or Deinara quests.

[raphoux69]

Can deianeira die in prison or not btw ?
There's also the fate of Albinius that depends on your choices and can remove further interactions

[=DeadShot=]

Originally posted by raphoux69:

Can deianeira die in prison or not btw ?
There's also the fate of Albinius that depends on your choices and can remove further interactions

Yes Deianeira can die in prison if you fail your dialog with her.