Lord of the Rings is a cooperative game for up to 5 players, playing against a game-programmed Sauron. A later expansion introduced a player Sauron, who plays against the rest of the playes. Another expansion, Friends and Foes, introduced further mechanisms, and Battlefields added a tactical battle aspect.
Each expansion contains elements that both oppose and aid the players, but overall, each one makes the game a little harder.
Up to today, I had player Lord of the Rings with both the Sauron expansion, and Friends and Foes, but not at the same time. I had never played Battlefields. My suggestion for the session was to play the game with all three expansions simultaneously. 3 other mad members of my gaming group volunteered to die horribly with me.
It was an absolute disaster, with Sauron winning multiple times, but we laugh so much, because it was so silly. The last game we dropped Friends and Foes, and just played Sauron/Battlefields, but still lost, but not as quickly. However, it was a fun day, and worth the experiment.
I was particularly taken with Battlefields, which I think would make the Base game + Battlefields a good challenging solitaire game. Must try it sometime.