Most expansion packs are released when the core game's popularity is beginning to wane, but that's not really the case with Diablo II: Lord of Destruction. In the time since it was released a full year ago, Diablo II has proven to have a very enduring appeal. Players have continued to pit their characters against the collective forces of hell and debate among themselves about which of the five original character classes is the mightiest. If interest in Diablo II has waned at all since last year, then Lord of Destruction will certainly rekindle it. This official expansion introduces two powerful new character classes and scores of other new features and enhancements that all serve not only to bolster the surprising longevity of Diablo II, but also to improve on virtually every aspect of the game.

The assassin and the druid are powerful new character classes.

The most obvious addition in Lord of Destruction is the option to choose from two brand-new character classes, bringing the total number of playable classes in Diablo II to seven. The original classes offered rather diverse play experiences, so you might be skeptical as to whether the expansion classes, the assassin and the druid, would be sufficiently different from the others. Fortunately, they definitely are. In fact, not only are these two classes notably different both from one another and from the other characters, but they're also quite powerful and provide a lot of different tactical options.

The assassin can become skilled in the use different traps, martial arts, and psionic abilities called shadow disciplines. The martial arts are quite interesting--using successive melee attacks, the assassin can charge up various moves that can lead to devastating and rather spectacular results. The assassin can also set up automated sentry defenses to attack her foes with elemental damage, and she has the unique ability to wield the new clawlike weapons found in Lord of Destruction. The druid character is no pushover, either. He can cast powerful natural spells that can rain fiery death down on his foes, create fissures in the earth, cause hurricanes, and more. The druid can also summon animal companions such as ravens, wolves, and bears, and he can himself transform into werewolf or werebear forms. Both the assassin and the druid look as good as all the other classes, and though each is well equipped to handle any particular combat situation, each can specialize in a variety of ways--so, two different druids or assassins of similar level may still have totally different proficiencies, depending on the players' preferences.

If you choose to play as one of these new classes, you must begin the game from scratch, in the very first act. Only after you play through the original four acts in the game will you be able to proceed to the new fifth act, in which your ultimate goal is to defeat Diablo's brother Baal, the Lord of Destruction. The fifth act featured in the Diablo II expansion is certainly the best of them all. Most of it is set around a barbarian village under siege by enemy forces stationed on a nearby mountain. As you fight your way up the mountain, you'll have to contend with powerful foes of all sizes, as well as their demonic artillery weapons. You'll then venture into ice-covered underground caverns and deep into the heart of the mountain, where you'll eventually face your final foe in a very challenging confrontation. This new act isn't just the toughest and most colorful of them all, but its six different quests are rather involved, and it's the also longest act overall--though it's still relatively short and probably won't take more than 10 hours to finish the first time. In turn, though the fifth act is noticeably different from the others, it still follows the same basic blueprint. That is, you'll constantly be fighting droves of enemy forces through expansive and sometimes mazelike randomly generated environments.

The fifth act offers numerous new challenges and rewards.

The Diablo II expansion includes a lot of other changes and additions to the original game, along with a printed manual that clearly and specifically describes them. One of the most interesting new enhancements in Lord of Destruction is in the way it treats hirelings, the computer-controlled characters you can hire in the towns at the beginning of most of the acts. In Diablo II, hirelings didn't offer any significant benefit, as you had no actual control over them and they weren't nearly strong enough to survive for long. Though you still have no tactical control over them in the expansion, now you can actually outfit your hirelings with armor and weapons and watch as they gain experience levels while fighting alongside you. For a fee, you can resurrect your hireling if he or she is killed, and you can even travel with your hireling from act to act. So, you can actually keep the same hireling with you throughout the entire course of your time spent playing as your particular character. Hirelings are still a liability in some instances, and they generally aren't useful against the boss monsters at the end of each act, but they're now a much more valuable part of the game.

Some of the other changes in Lord of Destruction affect the game's interface and how it plays. All these changes are for the better. You can now access an onscreen minimap instead of Diablo II's full-screen map overlay, and it doesn't clutter your view as much and is generally easier to look at. There are now convenient hotkeys for buying multiple types of common items, such as health potions, and for quickly dropping health potions into your belt for easy access in battle. The game also gives you access to eight additional skill hotkeys, so you can have as many as 16 different character skills mapped to your keyboard. Another very significant interface change lies in the fact that each character can now readily switch between two completely different sets of equipment in his or her hands. For instance, a barbarian might use two swords in most situations, but he can now switch to a more-powerful two-handed polearm with the touch of a keyboard hotkey. This new ability creates a major tactical advantage in many situations, just as it gives the game more depth of play.