Diablo practically popularized the hack-and-slash sub-genre of RPGs. Its apparent simplicity, however, disguised the presence of some clever game mechanics that made the game more sophisticated and fun than it looks. Diablo II, which is its direct sequel, builds on this design principle.
The story in the sequel is a continuation of the first, which had an ending that did not satisfy everyone who played the first. Diablo II offers a much better resolution to what happened in the first game. However, perhaps the development of the storyline somewhat invalidated the rationale for that of the first game. The first game had the theme that malicious forces can never be truly defeated, yet the player appears to get to vanquish some of them - major ones too - quite thoroughly the second time around.
As (also) to be expected from Diablo II, the story does not necessarily tie itself up at the end, leaving opportunities for a follow-up. Usually, cliff-hangers are risky proposals that may draw irate frustration as much as eager anticipation, but in the case of Diablo II, it had fortunately obtained more of the latter, at least from this reviewer.
Of course, the story of a game that is solidly in the hack-and-slash RPG sub-genre is essentially just there as an excuse to pit the player against hordes of enemies to be removed as efficiently as possible, with a huge side-dish of fun as a bonus. Diablo II does not disappoint here.
After a short exposition of what has happened since the first game, the player goes to the class selection screen and selects his/her favored class. All of them happen to be quite capable of playing the game from start to end - provided the player has an idea of what kind of character build that he/she wants.
That said, Diablo II is not for the hasty and brash. Haphazardly developing a character without any plan of how the player wants his/her chosen hero/heroine to turn out will result in an ineffective peon and a disastrous waste of time. Unlike RPGs of today (which had learned from the lessons inadvertently provided by Diablo II and the games before it), it does not offer any (in-game) means of re-tweaking the player character in order to optimize his/her performance. (The player can, of course, use external means, but this is an altogether different matter.)
It is somewhat a detriment to the game that it looks so deceptively accessible to players who are new to Diablo, when in contrary it punishes clueless players who would have to learn the hard, soul-crushing way that they had wasted their time and effort in progressing their characters.
On the other hand, if the player had done his/her research on character builds, he/she would have a great time with any of the characters. Players who did not do any research but did consider the next step in the progression of their characters would also have a good time too - though every leveling-up occasion is going to end up being a possibly nerve-wrecking decision that comes with risk.
Regardless of the character class used, the player will have to accrue experience by completing quests (which only provide relatively decent experience rewards) and killing evil and/or corrupted creatures/monsters. This experience goes toward reaching a threshold that once reached, results in a level-up. It is a simple game mechanic that requires little oversight and had worked well in previous RPGs before (namely Diablo), and it is right at home here where the combat is the focus of the game.
How the player would go about slaying monsters and completing quests (which also usually involve slaying monsters) is tied towards how the player uses the benefits gained from leveling-up to build his/her character. Unlike the character progression system in the first game, which was mostly about spending points in intrinsic statistics like Strength and Dexterity, the player character is also granted a skill point in addition to the usual stat points.
This skill point is relevant to a game mechanic that is new to the Diablo franchise, which are the skill trees. Every class has his/her own set of unique skill trees (three for each class), which are thematically related to the conceptual design of the class. The point can be (irreversibly) invested in any one skill in any tree with just a single mouse click, improving the efficacy of that skill.
(The skills are represented in the user interface with big huge buttons of decent contrast against the rest of the screen, but a request of confirmation for the expenditure of the point would have been an improvement in user friendliness.)
Skills may either be abilities that have to be actively used or ones that confer ever-present bonuses. Depending on their benefits and how they may be utilized, they are placed under categories, i.e. the aforementioned trees, that broadly describe the fields of expertise that the class is known for (in Diablo II's lore).
More so than statistics and equipment, these skill trees are the main focus of character builds. Every character class can be developed with a combat role in mind, but no two of them will be able to go about fulfilling the same role in the same manner; the skills available to each class are diverse enough from those of the others. This is in contrast with the design of the classes in the first game, where jacks-of-all-trades can be developed with any class, for example.
Moreover, a skill tree for one class can be so different from the other two such that informal sub-classes can be developed. A particular, visually obvious example is the Sorceress, who can invest in spell-like skills of different elements: a Sorceress who prefers to bog down enemies to give herself some room for escape would invest mostly in her school of ice spells, while another that prefers to just blow them up outright would favor the fiery spells instead.
This game design allows for many permutations of character classes - including useless ones, and hence this is the reason for the mention of the game's deceptive accessibility.
One of the major considerations in developing a character is that every subsequent skill point invested in a skill that already has points from earlier levels would give eventually diminishing returns. This discourages specialization, and forces the player to consider opening up the rest of the skill trees so as not to waste the points. On the other hand, this would give the player more versatility in handling enemies and obstacles that he/she would have to face in the future, as well as explore more of what the developers had offered to the player.
Yet, this deliberate game mechanic would have been of sound design, if not for the requirement that certain skills need to reach specified ranks before the rest of the trees can be opened up. Therefore, the player will be forced to waste some points through the mechanic of diminishing returns just in order to reach the skills that he/she wants. For example, the Barbarian class has some powerful melee skills that would be more potent than his first few, but to reach these, he will have to invest a few points into skills like Bash, which the player may hardly use ever again.
In addition, there is also a class level requirement that has to be met, and of which should have been more than enough as deliberately introduced gameplay-balancing restrictions.
Fortunately, like for stat points, the player can choose to hoard skill points for later use, though the buttons that indicate that there are points left to be spent will never disappear from the user interface and will continue to obscure the view of the player character's surroundings until the player has spent them. As each is big enough to cover the sprite of one small-sized creature, this is a minor but significant setback in a game that uses a point-and-click system.
If the player can get over these minor design flaws (which can be anticipated for through research on builds), the player will find that there is a lot of replay value to be had from this game from just the many character builds alone. For example, there can be several types of Barbarian builds, each of which have their abilities centered around the utilization of a different set of weapon load-outs. Each build would fare differently in a certain combat situation, and again differently in another one.
(For example, this reviewer had developed a Barbarian to wield the most ridiculously big weapon possible, and found that he made short work of bosses while being terrible against mobs. Similarly, this reviewer had an ice-oriented Sorceress that ended up taking a long time to remove mobs of bogged down enemies.)
Perhaps the more interesting classes are the ones that can make use of summoned/conjured creatures - namely the Necromancer, who through his eldricht skills can raise an army of undead (which includes a not-so-undead notorious brute). For this class, his army would be doing much of the busywork of hacking down enemies, which is quite a delightful departure from previous RPG conventions that had the player characters doing most of the heavy lifting.
Being a combat-oriented game, the development of characters are ultimately but for two main reasons: fighting and looting.
Looting is generally a by-product of fighting; slain enemies generally drop items all over the battlefield for the player to collect. For certain classes, even corpses would be a source of loot or at least replenishment of the resources that they have expended during the battle.
(In multiplayer sessions - more on these later - there is an especially amusing mismatch of party members that can be found from pairing slow-but-hard-hitting Barbarians with army-centric Necromancers, both of which fulfill the same role of "taking one for the team" but may be competing for corpses, which can mutually exclusively be either a source of potions or cadaver for summoning replacement skeletons.)
Loot can also be obtained from opening - or breaking open - containers, the act of which can offer as much glee as destroying enemies thanks to satisfying noises that indicate containers have yielded their contents.
Looting is of course one way of obtaining gear needed to trick out player characters. Gear can also be obtained as rewards from some quests. It can also be purchased from vendors, and unlike most RPGs where the best stuff are usually found instead of bought, the player can find some tantalizingly powerful items in vendors' lists of offered products, thanks to the randomizing mechanic used for vendors that had been improved over that in the first Diablo.
(Granted, most of the items on-sale would be worthless tripe, but there will be one or two that have exceptionally high stats that would catch the player's eye.)
There is also a vendor that offers items of initially unknown statistics, which will be randomized and finalized after paying a (very high) purchase price. With the inherent risks of wasting gold on a useless item, this feature is fittingly called "Gambling". Yet, due to a game design that ever replenishes the nests of enemies in the game world on a periodic basis, the player character would eventually be flush with gold. Without this feature, there would nothing else worthwhile to spend the gold on (if the player does not prefer the alternative of being ripped off by fellow players in multiplayer), so it is definitely a wise inclusion in the game.
In addition to weapons, pieces of armour and jewelry that players can equip on their player characters (as can be expected from most RPGs with looting as a theme), players also get to obtain trinkets that can be (permanently) incorporated into their weapons, shields and helmets (oddly enough, body armor may not be altered).
This mechanic is not entirely new, but its implementation in Diablo II is almost flawless. The trinkets include gems of various colours and (oddly enough) magical skulls, all of which have clear descriptions of what they would do when inserted into one of the slots of a piece of equipment that has them. All that tool-tip text may seem to hog much of the user interface, but then utilizing these trinkets, and checking out the properties of other items for that matter, is not something that can be done outside of tranquil areas in the game.
Perhaps the only setback that this equipment customization mechanic has is that alterations are practically permanent. There is no way to extract gems and skulls that had been incorporated into equipment (though their monetary worth will be added to that of the latter). There is nothing to reverse a slip of the finger on the mouse.
With all these sweet gear and the skills to make the most of them (and some would argue, vice versa, as well), there have to be enemies in the game that the player characters can use them on. Diablo II offers plenty of monsters to be slain in whatever manner that the player likes.
At normal difficulty level, monsters, which include melee-only brawlers, ranged attackers and support providers (e.g. healers, buff-casters and resurrectionists), may be tackled using approaches that mix caution with head-on onslaught, with only an occasional enemy that has to be taken on with greater care, namely the bosses and mini-bosses (who usually lead mobs of monsters of the same ilk). Unless the player had made mistakes in the development of his/her player character or is outright foolhardy, most enemies can be considered to have lost the moment the player has engaged them.
At higher difficulty levels (which are only accessible after beating the previous ones), enemies have even more properties that present greater challenges to the player, such as a total immunity to melee damage and ability to absorb elemental damage as additional health in addition to being immune to that completely. As a reward for confronting these nastier challenges and being triumphant, the player is able to loot much more powerful items that would be more suitable for these difficulty levels. In addition to encouraging replay, the challenges in these higher difficulty levels which would seem insurmountable to any single player provide an incentive for engaging in multiplayer (more on this later).
As Diablo is a sequel, it is unavoidable that it will be compared to its predecessor for any assessment of the changes that had been wrought to the gameplay of the first. Fortunately, this reviewer can say that most of the changes are improvements - at least to gameplay. One of the major changes involve the removal of spellbooks and scrolls, which have been rendered obsolete with the new character class system.
In addition, the player is also able to hire a special henchman to compensate for or further augment the total offensive power of the player character. This henchman is unique to a certain Act, or segment, of the story, and can be quite handy to have around. In addition, this henchman can become more powerful as the player gains more levels. Each major type of henchmen also has several variants, further increasing the range of choices that the player has to prop up his/her own character.
However, a type of henchman appears to be only unique to the Act that he/she is hired from. He/She will not follow the player character into other acts, for which the player will have to hire the ones who are unique to those acts. However, he/she will return if the player happens to return to that particular Act.
Moreover, henchmen are not fully fledged characters, and they die permanent deaths. Fortunately, getting a replacement is very simple, though he/she comes at a cost that can be easily wasted if the player picks the wrong kind of fight.
Another major change is the inclusion of belt items and how they changed the quick-item-use system. Player characters can now equip belts which will determine the range of potions that they can have available for a quick quaffing (which as usual, has no animations at all). By default, there is only a row of four potions that can be quaffed, but more advanced belts provide more rows that can be stocked with potions that will immediately take the place of the one in the same column that had been used up.
Theoretically, the player can have up to 16 potions for quick use, but will have only four that can be visually checked with a glance at any one. It will not take long for the player to realize that to be efficient, the columns will have to be filled with the same sort of potion. Ultimately, this practice also means that only up to four different types of potions are available for quick use, if the player does not want to memorize what he/she has stocked away in the belt.
It is a convenient yet awkward system at the same time, with the latter sense being reinforced whenever the player has to manually restock the belt with potions (which can happen after removing a dangerous mob).
Also, potions no longer heal or replenish mana instantly like they did in the first game. Instead, they take a while to achieve their full effect, which adds much required game balance that would have been absent if players are allowed to abuse the new belt system. (However, there is a special potion whose effects are instantaneous, but it is understandably rarer than regular potions.)
Another significant change is that the game-world will repopulate itself with loot and enemies - even plot-critical bosses - whenever players reload the game. (There can ever only be one saved-game per player character, and they will always start a reloaded game in town.) While this game design can certainly be exploited, it does seem to lengthen replay value and allows player characters that are too weak to confront plot-critical bosses an opportunity to beef themselves up.
Another addition to the game is the inclusion of waypoints, which somewhat function like the special entrances to certain levels in the main dungeon in the first game. However, unlike those entry-ways, these allow transportation between waypoints. A crafty player can plan efficient looting/fighting runs through these waypoints in between reloads of the game.
Fighting and looting in Diablo II occur in a game world that is randomly generated and added onto whenever the player character enters a new area that he/she had not stepped in before. Therefore, the locations of some in-game objects like enemy mobs and loot containers are not certain. What is for certain is that they will be there, in the area that has been predetermined to have them. For example, maps with bosses and mini-bosses are guaranteed to have them around somewhere, though the terrain of the immediate area that they are roaming around in may or may not be advantageous to the player character.
These maps generally stay the same and will be included in the player character's saved-game, though they may change upon joining another player's multiplayer session. It is an odd occurrence, but one that keeps the game somewhat fresh, as not every in-game object, e.g. shrines, will persist in a map like others will.
Much of the graphics consist of 2-D sprites and backgrounds. Their quality varies, but almost all of them are decent to look at, with some being exceptionally exquisite (especially those for the player characters). However, the game appears to have some problems with scaling resolutions: switching to a higher resolution only made everything smaller, suggesting that all the models used were suitable for only one single resolution setting in the first place.
Moreover, as exquisitely done as the sprites and terrain are, the random map generator can produce some ugly and unimaginative maps, with a lot of repeated textures and terrain-oriented sprites. The game also resorts to a lot of colour-palette swapping for expanding the variety of monsters. It also uses this cheesy technique for status effects (e.g. poisoned, frozen).
Very badly randomly generated maps will also be a pain to look at when the map overlay is toggled on-screen. The map consists of subdued squiggles and lines, but it can still clutter the screen and is all but useless in locations where the backdrop is of the same colour as the lines and squiggles.
Small but noticeable slow-downs also happen whenever there are lots of effects and sprites on-screen - which happens to be a common occurrence.
Patching did however eventually resolved much of the non-hardware issues.
The game sounds like what a hack-and-slash RPG should sound like: lots of grunting/groaning/screaming/screeching from the wounded and dying, the juicy slicing of steel across flesh, the din of fiery explosions, crackle of lightning, etc. As may be apparent already, much of the audio design of the game went into the aural enhancement of combat.
There are some decent music scores that are thematically appropriate with the current location that the player is fighting in, but the player would likely be more distracted by the sounds of combat than the music. However, some scores, namely those for towns, would be a welcome respite from the noise of combat after the player decides to haul his/her loot back for some cashing in and swapping of equipment.
The voice-acting for the myriad of characters is very satisfactory in bringing forth much of their personality. Most of the characters are newly introduced into the series in an attempt to extend the lore and background of the game, and all of them are voiced quite accordingly to the theme of their characters.
Multiplayer is apparently a very significant component of this game. Joining a multiplayer session sends the player into the game world of its host, so most of the changes wrought to that game world would only affect the host player. However, the guest player can complete quests in that session, which can be handy if the player is having some trouble completing a quest on his/her own. (However, if the host player completes quests within the same act that as the guest player, it can lead to some awkward advancement in the main plot when the guest player returns to his/her own single-player game.)
More importantly, multiplayer increases the toughness of enemies, and conversely the rewards that can be obtained from them. More loot, as well as more powerful loot, will be dropped from enemies (especially mini-bosses and bosses), to everyone's delight (or relief). Unfortunately, the game does not appear to have any system to share loot, so a quick-handed player would take most if not all of the booty, even if players happen to have formed a party (which appears to let them share experience gained from slaying enemies, even across acts).
If tempers flare (and it would if a loot-hogging player joins the fray), players can turn hostile towards other players and attempt to slay them. However, at best, this feature is only intended to aggravate the victims and sate the appetite of players who would prefer to commit atrocities against others instead of playing the game, because theoretically, there is no tangible reward for murdering other players. Slain players simply take a penalty to their experience gauge and gold reserves on their character at the time, like they do when they die under other circumstances, but they will never lose gold that has been stashed away nor will they lose character levels. Moreover, they have the option of safe-guarding their corpses from looting, a feature which does little to soothe any frustration caused by a loot-hogger.
(Of course, if the victim has chosen to create a hardcore character that permanently dies, that is a different case of aggravation. Even so, hardcore mode does not offer any actual beneficial incentives compared to regular mode, so it is at best a mere novelty.)
In conclusion, Diablo II, having been intended as a sequel and an improvement over its predecessor, has tremendously fulfilled this goal. Diablo II has made effective and popularized several game mechanics that greatly enhance the hack-and-slash RPG genre, and for this achievement, it would be the role model for many similar games to come.