The way I handle total defense is to say you have to be aware of something to be defensive about. Until you know something is there to be guarded against, even an invisible creature, then you can't use total defense.
I disagree with Tom about readied actions. Its only a standard action, and you can ready an action against preety much any condition. So I would allow you to move and have an action readied to attack the first thing that you see. (your dm may not let you get very specific, it depends on him)
However, if the Trog surprised you, I would have you lose that readied action, although a house rule could be that you keep it if you have combat reflexes.
Combat for you begins when you become aware of a definate threat. Here's how I do it.
1) If you become aware of your enemy before they are aware of you, you immediately get a partial action (surprise round). This could be attacking, or it could be jumping behind a rock. You are entitled to all combat tactics now. Whether you need to roll initiative at this point really depends on your dm.
2) If the enemy is still not aware of you, which is entirely possible if you don't take hostile actions immediatley, then you can start taking full round actions to prepare. I rule that if this is done, you won't be flatfooted when combat starts, your dm may feel differently.
3) Once the enemy has become aware of you, everyone rolls initiative and normal combat begins.
So for your scenario, let's say you were aware of trogs (a listen check to hear one of them talking).
1) You now get a partial action, you choose:
a) A partial charge. This is a surprise round. The trogs are flatfooted. You finish your action, and then everyone rolls initiative. And since they are trogs and your a lonely rogue, you die
b) A strategic retreat: You move silently back to your friends. Either:
I disagree with Tom about readied actions. Its only a standard action, and you can ready an action against preety much any condition. So I would allow you to move and have an action readied to attack the first thing that you see. (your dm may not let you get very specific, it depends on him)
However, if the Trog surprised you, I would have you lose that readied action, although a house rule could be that you keep it if you have combat reflexes.
Combat for you begins when you become aware of a definate threat. Here's how I do it.
1) If you become aware of your enemy before they are aware of you, you immediately get a partial action (surprise round). This could be attacking, or it could be jumping behind a rock. You are entitled to all combat tactics now. Whether you need to roll initiative at this point really depends on your dm.
2) If the enemy is still not aware of you, which is entirely possible if you don't take hostile actions immediatley, then you can start taking full round actions to prepare. I rule that if this is done, you won't be flatfooted when combat starts, your dm may feel differently.
3) Once the enemy has become aware of you, everyone rolls initiative and normal combat begins.
So for your scenario, let's say you were aware of trogs (a listen check to hear one of them talking).
1) You now get a partial action, you choose:
a) A partial charge. This is a surprise round. The trogs are flatfooted. You finish your action, and then everyone rolls initiative. And since they are trogs and your a lonely rogue, you die

b) A strategic retreat: You move silently back to your friends. Either: