Special events and gem promotions will once in a while happen in MQO. Gem promotions happen more frequently than special events. We have until now had 2 events.
There has only been 1 kind of event until now. A token styled event. You are getting tokens for activity and you can buy stuff for those tokens. The rate 100 action/1 token
Activity based event / Token shop Edit
This picture was taken in the Halloween/fall event (Hence the tokens changed to pumpkins). This is an example how the event shop could look.
You can buy some limited titles, boost your pumpkins gain to 75 actions/1 token for the event, and some different types of resources.