The maximum number of people allowed to enter Dynamis is 64, or 4 full alliances. In Dynamis the normal claiming rules do not apply, all 4 alliances can fight the same mob. Time allowed in Dynamis is exactly one hour from the moment a player trades a timeless hourglass to a set of trail markings. However, by defeating certain enemies, a group can extend the amount of time they are allowed in the area, to a maximum of 210 minutes. When a time extension is recieved, the length of additional time will be displayed in the chat log. A message will also be displayed if the time limit is nearing the end.
If a player leaves Dynamis, by death or by magic, they can re-enter Dynamis using the same Perpetual Hourglass at the same Trail Markings, but they will recieve what is known as "Dynamis Weakness". Dynamis Weakness is the same thing as normal raise weakness, except the max HP and MP are lower, and the time it is in effect is longer.
In each Dynamis there are a number of sub bosses that are killed in order to spawn a main boss. When the main boss is killed, there will be a ??? on the ground where the boss died. Examine the ??? in order to obtain the key item for that Dynamis, this will also change your title.