Interaction in Source Engine

[de_grim_reaper]

Is it possible for me to create a custom based interaction among characters using the source engine? I mean suppose in Counter Strike Source I interact with a hostage and instead of toggling "Yes, Ill follow you" or "OK, Ill stay here" everytime you press the 'E' or Use Key, can I have say a menu with say 5 different possible choices, and I can make any of those choices and depending on the choice I make, the hostage responds accordingly. I need to use the Source Engine for a kind of RPG game and this is a major consideration that needs to be addressed? I hope someone can help me here.

 

[Pesmerga]

Umm yes, it would require modifying the SDK.

Yes, it's possible.