Hi @chunchun123
I wrote my tutorial a long time ago and now the game has changed a lot since I wrote the tutorial.
There are other cards that generate passive income like stadium cards that generate Entry tokens that can be used to enter Splinterlands tournaments.
In the last months very high taxes have reduced the production of SIM tokens that, before, were worth a lot and were the main passive income of the game.
Dcity is a nice game but the management of taxes and other aspects of the game has not produced positive results.
I hope that in the future it will return to being the game it once was....
!BEER
RE: Dcity: Tutorial for beginners