Dungeons & Dragons 3.x – Too Many Traps
The first tabletop RPG I played was Dungeons & Dragons 3.5ed.
I recommend against 3.5 (or Paizo’s “3.75,” Pathfinder, which is really not all that different). It’s complicated and has a ton of rules, plus a lot of options that are (apparently intentionally) “traps” – stuff that looks good, but is really a waste of resources. Wizards had a very “ivory tower” design for it, and tried too hard to reward “system mastery” – which none of you have. It’s entirely possible that a 3.5 game would go great, but I personally would consider it risky – more likely people will be confused and people will wind up with wildly varying power levels.
Note that this is coming from an avid 3.5 player – I really do like the system. But it is not a good system for new players. I was only successful because I had a seasoned DM – which you guys don’t – and because I read about the system – both the actual rules and forum discussions – for a long time before I ever made a character. And I got a lot of help on that character (that thread has over 125 posts in it).
So 3.5 could work, but I really do not think it is a good idea.
Dungeons & Dragons 4e – Better Balance, But Still Complicated
Dungeons & Dragons 4e has a much better reputation in terms of balance and design. The rules are more consistent and Wizards actively avoided traps. It is still very much are “rules-heavy” system, though, and non-trivial to learn. Also note that unlike most of the other options presented here, you need to buy D&D4.
On the other hand, it’s the latest version of the most popular brand of RPG. There’s a ton of material out there for learning, there are plenty of players, and Wizards themselves have a lot of tutorials and the like – paying for a product does come with certain perks in terms of support that you can expect. That is definitely a plus; I can say from experience that the lack of these things makes some of the other systems mentioned here harder to learn.
Dungeons & Dragons “Next” – Not Done
Just a brief mention, since it may turn up in your searches: Dungeons & Dragons Next is a forthcoming edition of D&D that is still very much in its early stages. There are free playtesting materials available, but this does not strike me as a good way to learn, when the rules could literally be changing from week to week.
Legend – My Favorite, but Small and Still Rules-Heavy
My personal favorite system, Legend, goes even further to avoid traps, and also removes a lot of rules deemed more time-consuming (to learn or to play) than they were worth. I’ve seen a number of comments and testimonials from players for whom Legend was their first tabletop RPG, and the overwhelming majority of those comments were positive.
While I am definitely not an “absolute beginner” to Legend (I was a pre-release playtester), I did DM a group, of whom only one had played a tabletop RPG before. The game was quite fun, but I felt that I was guiding them through their actions an awful lot, and due to their busy real lives, none of them was really going and learning the system between sessions, and without doing that the game had a lot of trouble. I think Legend is a great game, and even reasonably good for newbies, for a tactical, rules-heavy game, but you do have to spend a fair amount of time learning before you can begin playing.
Plus, it’s a very new system with a very small following, being developed by an indy company; they only have one book and that book is officially still beta. It’s definitely playable, but it’s hard to give a recommendation to a work in progress.
Rules-Light Systems – Easiest to Learn and Get Involved In
And really, all of these systems are “rules heavy” and there is a good chance that this is not what you want. A rules-light system would probably serve a new group better – they tend to have fewer and simpler rules, relying more on winging it with whatever sounds cool/plausible, and things like mechanical combat abilities are less emphasized. Therefore, I recommend games like Risus or Mouseguard, which have very good reputations as rules-light games.
But I haven’t personally played either Risus or Mouseguard, I’ve only heard good things.
My Favorite Rules-Light System – FATE
My best recommendation, then, is FATE – it’s rules-light, it’s free, it’s pretty popular, and unlike Risus or Mouseguard, which I have not played, I’ve played FATE and can only say that I really want to play more of FATE. It’s a very good system.
FATE may not be as tactical as you like, but in my play experience it’s much easier to pick up. Our group was 100% new to the system (though not roleplaying in general), and we were playing the Dresden Files RPG (which uses the FATE system), despite only the GM being familiar with the source material. The game went very well, and I would say that our experience likely hindered as much as it helped since FATE is very different from Dungeons & Dragons – for everything we didn’t have to learn, there was something we did have to “unlearn.” The fact that the game went very well and was easy to pick up for us, I think, also means it would be relatively easy for even “absolute beginners” to do so.
For a heavily tactical RPG, you probably are looking for a rules-heavy system, but I’m not sure that there are any that are going to mesh well with the “absolute beginner” nature of your group. Such systems are complicated and have a lot of rules, which means usually new players join established groups who can teach them. Since you don’t have that, it may mean a lot of confusion, or someone sitting down and spending a lot of time reading and then finding a discussion group where they can ask all the questions they need answered to play. Dungeons & Dragons 3.5 or Pathfinder are probably bad choices. Dungeons & Dragons 4e is probably better, and the externalities (popularity, official support, etc.) are strong considerations in its favor. I personally like Legend better still, but it’s a small RPG without a lot of material or players.
Better systems for a group of only new players are more rules-light, however. These systems cannot offer as much tactical mechanical play, because they have fewer rules. Risus and Mouseguard are two such systems that I’ve heard are good, but have not played. FATE is a system I have played, and it’s very good. I strongly recommend it. I think it will probably be the easiest to pick up and play for a new group.