Talk:Boost/@comment-112.208.81.151-20121202142530/@comment-5689421-20121202143650

I'm no expert on these matters but I think the 30% bonus applies to the amount of XP your base card gains from the booster card.

[Leopardess] Tigra is a speed card

so as an exaple if a tac or bru booster card gives 100xp to a speed card, a speed booster card would give 130xp

so the attack and defence will be the same for any given level but you will have used less cards and silver to get there