D&D 3E/3.5 3.5 - Beating myself over combat rules :(

[KiloGex]

If I were you, since your error resulted in a TPK, I'd retcon the whole encounter and let the hidden PC try to disrupt the enemy's black tentacles with his lightning bolt. It seems only fair.

Rather than simply calling "My B" and redoing the entire encounter (which will give the players a heads up now that they now the BBEG's strategy and abilities), why not just say "Look, I made a mistake so I won't kill your characters completely." Instead, chose one of their deities and pull the divine champion card - "I see great things in your future, and your task is not yet complete" type thing. Drop them back into the world, with a compulsion to complete their task. Give them the -1 level for resurrection so that they don't just march right back to the BBEG and kick his butt, but maybe boost their XP until they return to the next level.

 

[Vegepygmy]

But the fact is that the standard action he can take during the surprise round can be "ready an attack".

Yes, that's what I explained in my first reply.

 

[Vegepygmy]

IMO the situation was tactically difficult:
Attack in surprise round (enemy is flat-footed, which possibly is a benefit because BBEG dex modifier was +5) and hope you will win the initiative, which you do. During the first round ready an action to disrupt spellcasting => Win.

Ready an action during the surprise round to disrupt spell-casting. However, the enemy rolls extremely poor initiative and finally when it's your time to cast a spell, your party is surrounding the enemy who is casting on the defensive. You fail your Wisdom check and cast the lightning bolt, thus killing your friends but the BBEG succeeds in Ref save and receives insignificant amount of damage => Lose?

The other members of the party should use the Delay action to let their hidden ally spring his "surprise attack" first. "Lose" => Win.

I'm not trying to justify anything, because I had a TPK but I sincerely - from the bottom of my heart - hope that no one sees this situation as a complete DMing failure.

Not in the slightest! I made a bigger mistake in my game last week, when I forgot all about light sources and had non-darkvisioned NPCs moving around and fighting just fine in complete darkness.

You just had the misfortune of making a minor error that had catastrophic consequences.

Note: Of course he could've yelled that his attacking with a spell, thus alerting his comrades not to get too close or in the way BUT BBEG would've heard it also.

(They didn't think to put a message spell on their scout, eh?)

 

[jefgorbach]

IMO, admit you goofed and redo ... with the hidden player declaration to use his surprise round readying the action to act should the BBEG cast a spell ONCE combat occurs.