The Kompu Gacha Ban: When Japan Pulled the Plug on 'Complete the Set'

Imagine a set of ten cards. Collect any nine, and the game congratulates you. Collect the tenth, and you win a super-rare prize. The catch: the tenth card is the one that almost never appears. In 2012, that simple trick was earning Japan's mobile game companies a fortune, and in a matter of weeks the government declared it illegal.

The trick was called kompu gacha, short for "complete gacha". In May 2012, Japan's Consumer Affairs Agency concluded that it broke the country's rules on unfair prizes, and the ban took effect on 1 July 2012. It was the first time a major government had stepped in against a gacha mechanic, and it reshaped how random rewards in games are designed.

How kompu gacha worked

In the early 2010s, Japan's mobile gaming boom ran on social game platforms such as GREE and DeNA's Mobage, which hosted browser-based card games played on feature phones and early smartphones. Players paid for random draws to collect cards.

Kompu gacha added a meta-prize on top. Each event had a themed set of cards. Pulling the full set, every single one, unlocked an extra-rare card that could not be drawn directly. The first few cards in a set came quickly, which felt encouraging. Then progress slowed, because the last missing card was usually rare and each new draw was more likely to give a duplicate than the one you needed.

The scandal

As kompu gacha spread, so did stories of players, including minors, running up enormous bills chasing the final card. Newspapers covered it, consumer centres received complaints, and politicians began asking questions.

In early May 2012, Japanese media reported that the Consumer Affairs Agency was preparing to rule kompu gacha illegal. Investors reacted at once: shares in GREE and DeNA, the two biggest social game companies, fell sharply on the Tokyo Stock Exchange. Later that month, the agency confirmed its view, and the industry was given until 1 July to remove the mechanic.

The companies moved quickly. GREE, DeNA and other platform operators announced they would end kompu gacha, and the industry soon created a trade group, the Japan Social Game Association, to write self-regulation rules.

What came after

The ban did not end gacha; it changed its shape. Japanese studios replaced kompu with designs that were easier to defend:

• Box gacha: a fixed number of items in a virtual box, so every draw brings you closer to the prize.
• Step-up gacha: a sequence of paid draws with better rewards or guaranteed rares at certain steps.
• Sparks and pity: exchange points or counters that guarantee a chosen reward after a set number of draws. Granblue Fantasy added one in 2016 after a player's costly, unsuccessful streamed chase for a single character. Our Cygames profile tells that story.

Japanese industry bodies also brought in voluntary odds disclosure, years before Korea and the US made similar demands. The wider legal picture is in our gacha law explainer.

Why it matters

Kompu gacha is the industry's founding cautionary tale. It showed that a game mechanic could be legal one month and banned the next if regulators decided it exploited players, and it proved that governments were willing to act. Almost every modern safeguard, from published odds to pity counters, traces back to the lessons of 2012.

It is also a reminder for today's designers. When a system works by making the last step feel close while making it very unlikely, players eventually notice, and so do regulators. For how modern guarantees protect players, read our pity systems explainer.