Guest Post: The secrets to Blood Brothers’ success

Editor’s note: DeNA’s Japanese RPG card battler has been a hit for the mobile-social gaming juggernaut since release. As Inside Mobile Apps previously reported, Blood Brothers’ events feature is wildly successful for the game. In a third guest post from Kevin Oke, lead designer at both Adrian Crook & Associates, a social-mobile game design consultancy, and PlayRank, a second screen startup, he analyzes the successful components of Blood Brothers from an outsider’s perspective. He previously wrote guest posts for Inside Mobile Apps which analyzed Supercell’s Clash of Clans and NimbeBit’s Nimbe Quest.

DeNA Mobage’s Blood Brothers for iOS and Android recently celebrated its one year anniversary, and is continuing to monetize very well, with an ARPU that has grown every month since release. With this milestone in mind, now seems like a good time to take a dive into the game and highlight some of the things this collectible card game (CCG) does well.

Although it’s certainly firmly rooted in the conventions of the CCG genre (“hands-off” battles, card fusion, gacha) Blood Brothers does add its own touches of innovation, as explained below.


Blood Brothers excels at player vs. player (PvP) on a number of levels, one being surfacing. Good surfacing ensures that players are not only made aware of key AEM (Acquisition, Engagement, Monetization) features and the benefits they stand to gain by using them, but also pushed towards these behaviors via smart timing and offering incentives. This is generally done through contextual dialog boxes and limited time promotions.

As PvP gameplay is traditionally a strong source of retention and monetization, it’s especially important to do surfacing well. Blood Brothers keeps PvP at the forefront of the player’s mind with random PvP battles while the player is progressing through a level. These random battles are effective in several ways:

  • Surfacing of PvP gameplay to get the player interested in it and strengthen its ability to help monetize and retain players.
  • Increases PvP’s effectiveness as a morale sink (morale being the rechargeable energy resource needed to engage in PvP and raid boss fights).
  • Clear, simple goals and incentives (winning streaks reward the player with items) — these suck the player in, extending sessions and draining the player of their morale as they attempt to extend their win streak to hit the next reward.

Although conceptually not unique to Blood Brothers, the inclusion of “all-out attacks” (more effective than regular attacks but three-times more costly in terms of morale) and high level raid bosses that are susceptible to them further help to keep morale a precious resource and make a micro-transaction refill more tempting.

Lastly, compared to the confusing and convoluted user experience (UX) that precludes getting into a PvP match in Rage of Bahamut, there is little such friction in Blood Brothers. Opponent selection filtering options are eliminated in favor of pre-determined choices, and it’s immediately clear to the player what’s at stake with rewards, and how their deck stacks up against their potential opponents.

Variety of Events

A steady supply of time-limited events is the lifeblood of a successful CCG, and Blood Brothers is no different in this regard. However the variety helps to set the game apart, with competitive and cooperative events. Team-based “tug of war” style events where standings update in real-time for control of fortresses are particularly exciting.

The real genius at play here is the use of time-limited events with dynamically updated standings and progress (a great source of tension), and short expiration timers for said events. These timers are tuned with the recharge time lengths for energy and morale in mind. This ensures that in order for the player to reach the upper echelon of rankings and rewards, they must spend money in order to keep their energy and morale topped up. This is a very well constructed monetization pinch, as the urgency and stakes at hand are a great source of pressure and tension for conversion to paid.

Interesting Decisions

CCGs in the mold of Rage of Bahamut have received some criticism for a lack of player agency or interesting decisions. Blood Brothers does innovate while maintaining a very tight compulsion loop, with skill transferring, branching paths in levels, and different party formations with skills that leverage these formations.

Pushing the Envelope on Retention

Mobage chose to push the envelope on daily login bonuses, as new users can earn one-time rewards of high grade cards after 10, 20, and 30 days (not consecutive) of logging in. This is smart as Blood Brothers appeals to a youthful audience that live on their smartphone and skew more towards “core” than “casual” in terms of gaming habits and tastes.

Additional Opportunities for Monetization

Strangely there are a few opportunities for monetization that haven’t been touched on yet by Mobage:

  • Re-specing cards — The player can earn stat boosting crystals that they can bestow upon the card of their choice. Allow the player to gain back any upgrade crystals they’ve sunk into a card.
  • Instantly evolve a card — skipping the need to hunt down a duplicate for the evolution to take place. For balancing purposes, this would need to be priced very high, and disabled for Legendary grade cards (the best in the game).


It may not win any core gamers over with its relatively linear gameplay, but Blood Brothers advances the CCG genre and points toward the potential for greater gameplay depth within it. As CCGs mature and the appetite for more complex social games on mobile grows, I expect this convergence will unlock that potential, yielding some innovative and fun results.