I'm at the stage now were I can start giving my enemy object(s) some "intelligence". I want to start simple by using pre-defined patterns but I have no idea on were to start. My idea is to have the "pattern" in a pre-defined script that can be loaded and parsed at load time. As simple example say a door guard moves from left to right and then back again. Any ideas?.
Sounds like you want a finite state machine. They are pretty good for 8-bit style boss AI.
Get it working using C++ (or whatever native language you are using) before bothering with scripts.
Well, its a good idea to start using patterns, rather than writing haphazard code.
But scripts are a bad idea, if you are just starting off, its important to know how it works.
As suggested by geon, FSM is the best approach for simple games.
FSM are the basic blocks of any solid AI architecture.
its really simple,
define a set of states, then define output for each state on certain input, it can also be another state
and it all works in simple code.
Don't forget some waypoints... but then again, what type of game are you making?