Firstly, you will need to create a location where the player will choose their starter. This may be a Pokémon Lab, or it may be somewhere else. For convenience, it should be an enclosed place with restricted entrances (e.g. indoor places can only be exited via a door). Place blank events around the choosing location, such that it is impossible for the player to leave without stepping on one. Each event will have two pages: The Professor's event should also have a page that depends on Global Switch 3 being ON, which displays text like: "Which Pokémon will you choose?"