They can be triggered by landing certain symbols or combos or by meeting certain conditions.
https://45.83.123.20/viewtopic.php?t=15429
http://forum3.bandingklub.cz/viewtopic. ... &t=1552629
http://forum3.bandingklub.cz/viewtopic. ... &t=1111089
http://forum3.bandingklub.cz/viewtopic. ... &t=1239961
https://mmomakemoneyonline.net/threads/ ... no.524804/
https://ufr-2020.front5.picapo.net/foru ... pid=348765
http://www.lada-xray.net/showthread.php ... post178570
http://forum.ruchkontroliwyborow.pl/ind ... 42.new#new
https://www.silencertalk.com/forum/view ... p?t=713484
http://forums.shlock.co.uk/viewtopic.php?f=2&t=449250
https://debate.socialism.nl/forum/showt ... tid=184281
http://ewmen.com/viewtopic.php?t=846679