A relatively big difference in Battlegrounds is that the level of the shop not only determines the chance to get stronger minions, but also the number of available units in each roll.

E.g. in the screenshot above, the shop is on lvl3 (the three stars on the left of the tavern keeper), which means it has a total of 4 units for each roll. This gives an additional incentive to upgrade whenever possible, which is needed because low-tier minions can scale better in Battlegrounds compared to the other games in the genre (more on that below).

At the same time, leveling-up doesn’t increase your own board size (you can have 7 minions from the start of the game).