Heroes of the Storm's 2.0 update adds loot boxes and a familiar face from Diablo 2

Blizzard has announced Heroes of the Storm 2.0, an update for the free-to-play MOBA that introduces a new reward system, new currencies, new items and a new hero.

Both per-hero and account level caps are being removed and experience curves flattened out to offer much faster leveling overall. Every time you level up, you'll receive a loot chest which has a chance to contain any item in the game - including new heroes, although these will be rare. At specific intervals - every 10 hero levels, for example - players will also receive special chests with guaranteed rare drops for that hero.

"The progression system was one of the areas where we really felt that we could do better," senior game producer Tony Hsu said. "One of the things you encounter with progression, is it feels good until you hit the level cap.

"For example, Stitches is my favourite hero - and man, that slog from level one to level 20 is... somewhat rewarding, but once you've got that level you're no longer really feeling good about it. Once you reach level 20, you're not even getting rewarded any more - to me as a player, that felt like 'stop playing Stitches - you're not getting credit any more so go play someone else'."

The system is not fully random, with drops of greater rarity guaranteed to occur after a certain amount of time - placing a limit on how unlucky players can be. You'll also be able to spend a small amount of gold to re-roll the contents of chests if you don't like what you get.

The progress of existing players will be carried over into the new system based on how much XP you've earned, not the level you reached. Having a hero at level 20 currently, for example, means you've earned enough XP to reach level 55 under the new system - so that's where you'll be boosted up to. Players will also be granted loot chests based on their existing progress, up to a cap of 70 free chests.

Those chests will include loads of new cosmetic items, including Dota 2-style hero emojis and Overwatch-style spray decals. More specific to Heroes of the Storm are personal banners, which appear over destroyed forts and captured objectives - a flashy way of scrawling 'I woz ere' on somebody else's stuff, essentially. There are also new voice packs to replace the default announcer.

Diablo 3's version of Diablo - also known as Prime Evil and/or Lady Diablo - makes an appearance as a chest-exclusive skin for, well, Diablo, obviously.

All of this stuff will be organised into a new collection interface, which lets you save three cosmetic loadouts for each hero. Duplicate items received from chests will break down into 'shards' (see also: Hearthstone's dust), which can be used to craft specific items from the collection. The game's real money pricing is also being retired, replaced with a new premium currency, gems. You'll still primarily be earning gold through matches and quests, but this is now intended to be used almost entirely for unlocking new characters. No more splitting your funds between the skin you want and the character you feel like you need.

These changes feel like a modernisation of Heroes of the Storm's business model, but strictly within the parameters of contemporary free-to-play design. A faster and more rewarding progression system benefits players bored of the current grind, but it's also fundamentally a change focused on player retention. It's certainly not as radical as that '2.0' moniker would imply - although Blizzard stresses that the number represents Heroes' progress since launch, not the importance of this specific update.

The 20th anniversary of Diablo is being commemorated with a new hero, Cassia - the Amazon from Diablo 2. She wields a javelin in one hand and a shield in the other, and gains a bonus to physical protections as long as she doesn't stop moving for very long. This makes her an interesting duellist who places a lot of emphasis on the skill of 'stutter-stepping' - moving between each auto-attack.

Her abilities include a dashing flurry of strikes and a javelin toss that splits into two projectiles that fly out at 90 degrees from the point of impact. She also has an AoE blind with a passive component that makes her do more damage to blinded targets - giving her natural synergy with a few other characters, particularly Johanna.

"Cassia brings implications to the draft," said Tony Hsu. "Maybe I've never thought of putting Johanna together with Cassia, or Li Li with an assassin - in other cases you might take Brightwing for mobility. Now that I get synergies with blinds, maybe Cassia's the better option along with Li Li. It gives you a different perspective, a different lens of how you want to play the game and which characters might interact with each other."

Of her two ultimates, Ball Lightning is the most straightforward - she tosses a ball of electricity that bounces between targets a finite number of times, although you can remove this cap at level 20. Her other ultimate, Valkyrie, summons a ghostly warrior who impales an enemy warrior and delivers them to Cassia in a straight line. Why an Amazon inspired by Greek mythology has the ability to call upon a Valkyrie inspired by Norse mythology isn't clear: presumably they belong to the same union.

Beta testing for the 2.0 update begins this week.