i dont own IA, so i didnt play so ofthen like i do with Descent, so if somethings obvious please excuse me in advance.

I know that in IA all events and stuff are secret for anybody but the Imperial Players, but when there are optional objective that are in the "reward" session, is still a secrets?

Actual situation: we have played and win a mission on Hoth. We had toi defend terminals from beign destroyed for 8 turns. There was also like 4/5 doors that the IP had to broken in order to come closer to the terminals. At the end of the mission if the IP had destroyed ALL the doors on the map he will get (despite winning or loosing) an additional 2 influence as reward.

now is this suppose to be a secret information? i mean is not an event(according on what is an event on the rulebook) is an optional objective for the IP. An objective that we should try to prevent it from beign completed if we were aware of it

You read each event fully (flavor text and the rules section) when and if it happens, not before. This applies to mission briefing and end of mission sections as well.

You never read future sections to the rebels! (You can be asked to read out any of the already read sections though.)

Yes, in the mission you refer to the bonus objective is secret until the end. There a couple of similar bonus hidden objectives in the core box missions.

Technically you read the whole rewards sections when the mission ends. You read the appropriate end-of-mission section, then the additional rewards section in full.

However, as a house rule I only read the additional rewards for objectives achieved, not the parts that the rebels or the imperial player didn't achieve. (Unless it's of the form: if X happened, rebels get Y, otherwise IP gets Z.) I think this improves replayability, although with the amount of content currently that would not be an issue.

but isnt in this way impossibile to prevent such actions for the heroes?

What makes you think the rebels are intended or expected to prevent a hidden imperial objective?

The rebels know their objective, the imperial player knows the imperial objective. If the imperial player cannot reach their objective, at least it might be possible to gain something else by fulfilling a secondary hidden objective. If the IP doesn't manage even that, the rebels get a boatload of rewards from the mission, more than they generally get from a mission. Knowing any secondary objectives would make it even harder for the imperial player.

I have a question - if an event says "At the end of round 1, 3 and 5:" (as in Temptation), do you tell the Rebels at the end of round one that it will happen at each of those times? Or do you just tell them it's happening right then?

I'd only tell them the particular trigger.

Not sure if this is technically allowed, but I might not even tell them what the trigger was, just that there was a trigger, to allow more suspense the next time. In many cases it's obvious but there are a few 'end of the round the door was opened' type triggers where they won't know exactly what it was.

Paul has said to read the whole trigger. The rebels will then know that it will happen again, but there are not that many of these.

You can house-rule depending on your group. I originally read only the part that triggered, but I will go with the RAW now, especially for play by forum.