What is RpTools?
RpTools is a set of tools meant to give a virtual tabletop for pen and paper games. At it's core is MapTools which contains a chat interface, a dice rolling system, a map with grid and customize-able tokens which can even track stats.
How complicated is it?
For the players connecting to the Dungeon Master's server, it's fairly easy to get used to the controls, but the interface is far from intuitive, and at least simple instructions will need to be given to players.
For the Dungeon Master... Things can be very complex, which is part of the beauty of it:
You will find yourself able to draw maps, place items and objects around, create custom tables for stats and drops and encounters, create maps with lighting and FOV effects, program macros so that users need only press a button to calculate damage rolls (even so far as taking into account bonus modifiers from stats and status effects).
With all of this, you can craft a detailed world, which, once completed will facilitate game-play. No more looking through the rule book to see how much damage that one spell does, press a button, and it's all calculated before your eyes.
This sounds too hard, I'm out.
Wait! It doesn't have to be that hard! People on their forums have already created detailed macros and such for most of the popular pen and paper games. You just add it to the program, and then you use their built in character creator tools etc. It's still some work, but the more effort you put in, the less effort people need to give to play.
The tools available will make it so a tech savvy DM can guide newbies through an immersive and easy to understand experience, taking emphasis away from roll calculations, and putting it back on the game-play and story.