As with the other Guild Wars campaigns, the maximum level for all characters is twenty. Nightfall strikes a middle ground with the other Guild Wars campaigns with the amount of time spent leveling; faster than Prophecies, where much of the game is spent achieving level 20, but slower than Factions where level 20 is very quickly achieved.
New PvE-only skills have been introduced available by gaining ranks in titles. The "Sunspear Rebirth Signet" is available by reaching a certain rank in the Sunspear Rank track, and each profession has been given a special Sunspear skill that increases in power as the player's Sunspear Rank increases. "Lightbringer's Gaze" and "Lightbringer's Signet" are available upon reaching level 2 and level 3 in the Lightbringer track, respectively (these skills also power up as the player's Lightbringer Rank increases). Also, wearing the skill title "Lightbringer" increases damage done to certain creatures in the PvE environment. Gaining higher ranks in the Sunspear and Lightbringer titles also awards players with hero skill points, which can be used to unlock new skills for themselves and their heroes to use; while buying skills with regular skill points (earned by levelling up and completing missions) can still be used to gain new skills, this method only allows you to unlock skills from the player's chosen professions; using hero skill points allows you to unlock skills from any profession.
Further benefits of title tracks have also been integrated into the game since; for example, the player's ranks in the Lucky/Unlucky (gained by playing various in-game gambling activities) and Treasure Hunter (gained by attaining "rare" items from chests) title tracks aid the player's chances of lockpicks not breaking when opening chests and reducing the chances of an item being destroyed when salvaging upgrade components (such as runes, which increase attributes).
PvE has been expanded when compared to the previous chapters; some parts of the game draw parallels to single player RPGs such as Knights of the Old Republic or Baldur's Gate. For example, the player has to undertake a certain Nightfall mission alone, without the use of Heroes, henchmen, or other players. The mission requires very little combat and actually consists of a series of mini-games. Another example is a mini-mission that involves the player acting as a lawyer in a court case, where choosing the right line of argument will alter the outcome of the trial. The ability for the player to choose a course of action brings the game closer to its offline counterparts as opposed to the linear mission structure in other Action RPGs, as well as Guild Wars Prophecies and Factions.
The addition of Heroes has also made the game similar to single player RPGs, as most Heroes have their own side quests the player can complete if they choose. Depending on which Hero you bring on quests, they make different comments on the current situation, whether remarking about ease of enemies during battle or random comments while standing around. Heroes also allow more freedom when playing as a single player with only computer controlled party members since they can be given more commands than ordinary henchmen and their skills can be tailored to specific situations. The addition of commands and customization makes many challenges that would have required other human players without Heroes possible. However, although the maximum party size is eight, the maximum number of heroes that each player may have in the party at any one time is seven. The hero system has also led to many Guild Wars players highly recommending Nightfall as a good starter campaign for newcomers to the game, as it encourages more strategic thinking and also makes playing PvE more straightforward (as especially in the earlier stages of the game, heroes may be of a higher level than henchmen and offer a better degree of survivability). This advice is not always sound since Heroes need to be equipped (which can be very costly) and their skills need to be unlocked (except for their starter skills).
Mission structure has also changed somewhat. Like in Factions, bonus rewards are dependent on the performance during the mission, not just one side quest; however, the bonus could depend on something like killing certain creatures or preventing others from dying. For all but the last two missions, a certain hero must be in the party before the mission can begin. There are three pairs of missions where either one or the other must be completed before the plot progresses. Two of these pairs are selected depending on which hero was added to the party early on, while the third mission split offers a choice to the player. All the missions can be completed at the appropriate place in the plot, either depending on other players or by waiting until the plot has been completed (at which point players may gain all the heroes that they had previously chosen not to take).