3. Item drops
Encourage players to not stay in a corner but keep moving. Not sure if this one can be applied to Original Sin.
It takes action points to loot during combat, and you can toss gold on the ground to distract greedy or stupid characters (lava, being 'shiny' can also distract stupid characters, or normal characters under a curse that lowers their intelligence).
as far as I can see Original Sin is a combination of these. I'm not exactly sure how it works though. Am I right in thinking it goes in order of initiative and each character uses all their action points and then it goes to the next character?
Yes. The initiative for the first round is also dependent on whether it was a surprise attack, or not, so if you initiate combat without the opponent(s) seeing you, you go first (and vise versa).
I think for Original Sin, if your character can attack a few times depending on their action points this really changes the optimal number.
Yes, you can attack multiple times if you have enough action points. A level 1 character in the initial area shown in the gameplay videos can move a longer distance, move and attack, or attack twice (presumably higher level characters, depending on their stats, will be able to either attack additional times or use stronger attacks that take more action points).
ok I still swear I heard 4 but after hours of watching DOS vids on youtube and not finding the one I remember it in.
Multi-player is limited to 4 people (main characters and henchmen). Maybe you were thinking of that?