From Mabinogi Duel Wiki
A certain VIP level gives you a couple of benefits in the game. The higher the level is, the more/better benefits you will have.
The current maximum VIP level is 15. It is only possible to raise the VIP level by buying items on the shop page with real money.
The VIP level is especially important for traders, since it directly affects the tax rate of sold cards.
VIP level details[edit | edit source]
When clicking on the VIP level in the hero selection screen, the player can see even more details about the VIP level. The progression rate of all bonuses and the tax especially are listed there.