Hard mode

Hard Mode is a new addition that presents each mission and explorable area again on a harder difficulty. It basically adds a much harder version of everything to the existing game. Entering areas in hard mode gives a +50% exp bonus, and completing missions and bonuses contributes to "a Guardian Title Track". If a party is wiped while all party members are at 60% death penalty, the party will be taken back to the last visited outpost.

Hard mode is available in all areas of the game except for Pre-Searing Ascalon.

Accessibility
The Guild Wars Hard Mode Fact Sheet released April 19, 2007 states that in order to access Hard Mode, the player must have completed a campaign in Normal Mode, after that all other level 20 characters on the account will gain access to Hard Mode for that campaign. Hard Mode is toggled by switching between two buttons above the party display in an outpost, the Normal Mode button being the standard mission emblem, and Hard Mode a stylized red helm.
 * In order to unlock hard mode for a given campaign, a player must log in at least once after the hard mode update with a character who has completed that campaign in normal mode

Monsters

 * Monsters will receive significant adjustments, particularly the monsters which are low-level in Normal Mode.
 * Gaile Gray stated, "So, if you've ever wanted to explore a version of the Flame Temple Corridor with level 20+ creatures, you'll be able to do that with Hard Mode." Follow the link at the bottom of the page to see her whole statement.
 * Monsters have a 50% attack speed boost, a 50% shortened recharge time of all skills, a 50% run speed increase, and 50% decrease in casting time.
 * Monster levels seem to vary between 22 and 30 depending on their original level, with a few "training" monsters like caged enemies and targets are level 20. Certain unique foes, such as Shiro, are as high as level 33.

Items
Hard Mode will introduce new items which will only drop in Hard Mode. Hard Mode introduced lockpicks, which are similar to keys, but can be used on any locked chests in both modes, and have a chance of not being consumed on use. The chance of them working and the chance of them breaking is determined by your character's level, and Lucky and Treasure Hunter titles. Other items of interest include tomes, allowing your character learn skills that have been already unlocked on your account. There is an Elite Tome and a Non-Elite Tome for learning elites and non-elites respectively. Passage Scrolls can be used to enter the Underworld or the Fissure of Woe without paying the entry fee. They must be used in the typical entry points for these locations. Also, the Luxon Scavenger in Cavalon now gives a Deep Passage Scroll, which allows access for one person to the staging area, this costs 1,000 luxon faction. The Kurzick Bureaucrat in House zu Helzer also gives a Warden Passage Scroll, which allows passage for one person to the staging area, this costs 1,000 kurzick faction.

Titles
Hard Mode added the Guardian and Vanquisher titles, and makes the maximum rank of the Sunspear title track attainable. Legendary Spearmarshal now requires 50,000 Sunspear points for maximum rank. It also greatly speeds up attaining the maximum Lightbringer.

Sunspear skills
Although not technically part of Hard Mode, several new Sunspear skills will be added in a future update soon after Hard Mode is released. New profession-specific Sunspear skills will also be added as part of the increased sunspear rankings.

Changes to Normal Mode
When Hard Mode was introduced, the AI of foes in Normal Mode were changed slightly to make it a bit easier. Normal Mode monsters now:
 * Take more time to run out of AoE damage.
 * Are less likely to kite for long periods of time.
 * Will, in the case of melee monsters, focus all their attacks on the same target.

The Hard Mode AI is now the most advanced AI ArenaNet has available, and may be improved in the future as ArenaNet finds ways to make the enemies "smarter".

There is now non-linear loot scaling based on party size. A player with a full party will receive roughly the same number of drops as before, while a solo player will receive significantly more loot than they would in a full party, but significantly less loot than they from soloing prior to the update. The exception lies with the drop rate of rare items, Green items, Tomes, Dyes, special event items, Gemstones, and rare crafting materials. Thus, there is little advantage to soloing in Hard Mode if you do not want these items. (Indeed, if you were with a full party and someone else got a drop you wanted, you might be able to buy it off them.)