View source for Bakugan Wiki:How to Play (Generation 1)/Japanese Version

==Rolling==

On your turn, you can roll your Bakugan, add new gate card on the field next to, behind or in front of one of gate cards on field and/or play certain Ability Cards (ones that take effect before or after your roll).

You must roll your bakugan from distance of at least 2 gate cards from closest one on the field

If your Bakugan opens on roll and magnet is connected to your card, then your Bakugan performed '''Stand'''. If you performed Stand on gate card with your bakugan - you take this card and put it into your Used Pile (aka Winning Slot). This is called '''Double Stand'''. 

If there is an opponent's Bakugan on the Gate Card, Battle ensues.

If you performed Stand on Gate Card with ally (but not your) Bakugan, Stand fails

If you miss your Bakugan, that Bakugan is placed in your Unused Pile.

In any situation when bakugan loses magnet contact with Gate Card and don't gain it once again, he should be placed in it's owners unused pile. If bakugan was knocked from standing of by opponent's bakugan which isn't Standing after that, that is called '''Critical Hit'''. When Bakugan was knocked off from standing of by opponent's bakugan that performed Stand after that, it's called '''Critical K.O.'''. Player who did Critical K.O. moves Gate Card on which his bakugan performed Stand to his Used Pile

If all of your Bakugan are on the field and you have no Bakugan in either your Used or Unused piles, then you can pick a Bakugan on the field to "Stay". If your turn comes around and the Bakugan you called "Stay" on is still on the field (ie. a Battle hasn't started yet with that Bakugan) then you get to take Gate Card where it was standing on.