Challenge

Current Challenge: Ace Green Arrow

Challenges is a game mode that can only be accessed during challenge events, which are held twice a week. It requires an account level of 10. Their respective challenges are the primary source of several heroes' shards and their gear.

Difficulty	Energy cost	Number of shards
I	6	1-3
II	9	2-6
III	12	4-11

Each challenge requires a certain class requirement (e.g. "two AGILITY CLASS heroes") for its three tiers (requiring 1, 2, or 3 of the class depending on difficulty). Those matches are represented in 3 different tiers of difficulty, I, II, and III, with one successful battle in a tier required to unlock the next. This unlocking is kept between rotations and does not need to be done again when a challenge returns.

Each tier's battle can be completed twice before a reset may be purchased, with each successful battle yielding a number of the event character's shards depending on difficulty (higher numbers are less likely; 6 shards from II is rare, for instance) and a drop chance of one of their gear pieces. You can reset each tier's battle up to three times a day for 50/100/200 gems, respective to the reset number.

Each challenge has Modifiers to one or more setting in the battle, including at least one that is player-friendly.

Challenge battles do not yield account or character experience. Sim Chips can be used on them after an update. 3-star completion (winning without suffering a knockout) is counted even if you did it before the update.

Losing challenge battles do not cost Pips. This can be exploited to complete League Missions; you can simply enter and lose a fight endlessly and every one will count towards "Complete battles using any [class] hero" missions, as long as time permits. This can also be useful for trying out new heroes without being limited by your Pips but will still expend your Energy.

Challenges list

Hero	First release	Requirements	Modifiers
Speedforce The Flash	05/12/17	Agility Class Heroes	Agility heroes
Warrior Queen Wonder Woman	05/19/17	Tech heroes	Stunning an opponent disables their specials for 10 seconds
Soulstealer Doctor Fate	05/26/17	Agility heroes	REGENERATION: Doctor Fate regenerates health over time POISON: Player DOT attacks deal +100% damage
Last Laugh The Joker	06/3/17	MIGHT CLASS heroes	ANTI-AGILITY FIELD: Might heroes on the player's team gain a large boost to the damage they deal
Entangling Poison Ivy
Sub-Zero	18/7/2017	Meta class heroes
Powered Supergirl	22/7/2017	Tech class heroes	ANTI-MIGHT FIELD: Tech heroes on the player's team deal increased damage when using Basic attacks and Abilities against Might opponents.
Hellboy		Arcane
Powered Supergirl		Might class heroes
Grid		Tech class heroes
Silver Banshee		Metahuman class heroes
Cheetah		Agility class heroes
Raiden		Tech class heroes

Trivia

• Difficulty II and III used to cost 12 and 18 Energy instead prior to update 1.5.
• Challenges used to require a character type (e.g. a Batman character) but now they always only require a class.
• Certain challenges are events in which up to double the normal amount of shards can be earned. They include the debut of Silver Banshee, Last Laugh The Joker for April Fool's, and Sub-Zero and Raiden for the anniversary of the release of Mortal Kombat X mobile, when it was also announced it is to be re-branded as simply Mortal Kombat mobile.