KirriCorp has applied a number of fictional errata and modifications to the English language rules of Duel Masters™. Through large amounts of research which has mostly been presented through the Fan Fiction, certain conclusions about the state of the game were reached, and applied, in the following order:

1. Around the introduction of set 8 of the game, Epic Dragons of HyperChaos, the card Corile was errataed to reduce its power and remove the 'draw lock' capability of it, since it could be seen to often have the effect of causing an opponent to skip entire turns. Specific reasoning and the outcome report of the research is available here.

2. After noting the extreme decrease in 'power' of the 'Disruption' deck style due to this, and the trouble caused to this deckstyle by aggressive decks using Searing Wave, or in some cases other Disruptive decks that got their Searing Wave first, this card was also errataed due to its ability to destroy large fields of effect creatures with minimal penalty. Specific reasoning and the outcome report of the research is available here.

3. Even before Cranium Clamp became available in Fan Fiction play, it was subjected to an errata, due in part to the fact that its original incarnation Skeleton Vise was limited to one in Japan, and secondarily to the observation that in certain situations, whether or not the discard was random, or not, mattered little to the devastating nature of the card. At this time, the only available anti-discard card was Dava Torey, Seeker of Clouds. Specific reasoning and the outcome report of the research is available here.

4. Before the card Bombazar, Dragon of Destiny, became available in Fan Fiction play, it was removed from existence, primarily due to the projected effect that it would have had on the play environment, and secondarily due to it being banned in Japanese play, which KirriCorp aims to approximate to a minor extent. It was later introduced into KC play due to a suitable errata being proposed by Nerafim. Specific reasoning and the outcome report of the research is available here.

5. Before the card Soulswap became available in Fan Fiction play, it was subjected to an errata, due to the uses of it in aggressive decks outpacing the usefulness of nearly any other available card, since it could act as both defense and blistering offense. Specific reasoning and the outcome report of the research is available here.

6. Around the introduction of set 10 of the game, Shockwaves of the Shattered Rainbow, into Fan Fiction play, massive research was conducted regarding the ability to play more than 40 cards in English decks, an ability not afforded to Japanese play. After much deliberation, it was decided to add the restriction to 40 cards as well. Specific reasoning and the outcome report of the research is available here.

7. The card Judgement of the Flame's Spear and the Water's Blade, though not available in Fan Fiction play, was removed from existence, due to the projected effect on the play environment, and also due to being limited in Japanese play. Specific reasoning and the outcome report of the research is available here.

8. The card The Grave of Angels and Demons, though not available in Fan Fiction play, was originally removed from existence due to the projected effect on certain decktype. Since then, this has been rescinded due to a lack of mathematical reasoning to support that decision (note that the Site Administrator still opposes the card and seeks such reasoning). Specific reasoning and the outcome report of the research is available here.