Party Formation panel

From Guild Wars Wiki

The party formation panel shows the current members of your party, and the allowed number of members in your party. As you progress through a campaign, the number of allowed members will increase.

[edit] Hardmode

When you have completed the final mission in a campaign, an option for Hard Mode will appear. You can choose to party with other players who are eligible for Hard mode. However, if a player who is not eligible for Hard mode joins your group, your party will receive the following message:

Hard mode has been disabled. (player name) does not meet the requirements for Hard mode. The ineligible player will need to leave your group before you can re-enable Hard mode.

Players using the Party Search panel to seek out other Hard mode players will have a [Hard Mode] tag in the description field by their name.