The game takes place at a playground where the players, while controlling groups of kids try to collect as many "happiness points" as they can in 9 rounds by building sandcastles or taking nice pictures of the flowers and insects with their mobile phones. But the cat prowling around the ground can spoil their plans. The players have to take into consideration their opponents' moves to compete with them or even to avoid conflicts in order to accomplish the missions.
In Grund, each player controls a bunch of kids at the playground. At the beginning of each round the cat has to be moved to another tile on the board by randomly drawing a movement card (it will affect the tile where it stays). After that, the players have to move all their kids to an adjacent tile (or even further if consuming energy points), one after another in turn. There are special tiles where only a limited number of kids can stay at the same time.
Once all the kids have been moved, it comes to "conflict" on the tiles with kids belonging to different players to decide who rules the tile. The competing players have to bid energy cards, the one who offers the most will rule the tile (the bidden energy cards have to be exchanged). The winner performs the tile action. The actions can be as follows: get an additional sandcastle part, get a photo of a flower/insect, get an energy card, draw a chance card, call an additional kid onto the ground for 10 energy points, get "happiness points".
At the end of the ninth round it comes to the evaluation. The players get "happiness points" for their sandcastles, photo collections, energy points and accomplished missions.
Grund is a combination of a worker placement and a deck building game where your situation awareness, tactical, strategic and trouble solving skills are challenged.