Hellgates are encounters available starting at Level 10 which typically require multiple players to defeat. When attempting a Hellgate encounter, Hell stamina is spent based on the cost of your Hellgate party. They come in two varieties; Hell Monsters and Hell Bosses.
Hell Monsters appear after completing a quest and are ranked levels 1-12. With a sufficiently powerful Hellgate party and more than a little luck, it is possible to defeat a Hell Monster in one go. Should that not happen, you and anyone on your Friends list will have two hours to finish it off. Once defeated, participants are ranked based on the amount of damage they inflicted and receive rewards based on these rankings. The player who first discovered the Hell Monster receives an additional reward. For Hell Monsters of levels 1-11, this reward consists of Hearts. The discoverer of a level 6 Hell Monsters will also receive a Wine. Level 12 Hell Monsters give out chests for the top five players and Hearts to everyone else. If the discoverer of the Hell Monster lands the killing blow, an option is given to immediately take on the same Hell Monster at one level higher (unless the one defeated was level 12).
Hell Bosses are open to everyone and stay around until defeated. Due to the massive amount of hit points they possess, it is effectively impossible to defeat a Hell Boss in one go. Once a Hell Boss is defeated, another will appear twenty-four hours later. Participants are ranked in two separate categories; amount of damage inflicted and number of blocks destroyed. All participants receive a reward in the form of a small number of Gems. Should a participant place in a specified rank and/or a sufficiently high percentile in either or both categories, additional rewards are received which can consist of more Gems, as well as Tickets, Equipments, and Cards.
Instead of expending Hell stamina, players have the option of using an Attack 5X against a Hell Boss. As the name implies, the amount of damage your Hellgate party inflicts is quintupled. Otherwise, it works the same as a regular Hellgate encounter. The first Attack 5X against a Hell Boss is free, with additional attempts costing either ten Gems or five Wine.