Wilds are simple but effective, and they also pay as regular symbols.
http://forum.ruchkontroliwyborow.pl/index.php?topic=80889.new#new
http://forum.spolokmedikovke.sk/viewtopic.php?f=6&t=1047087
https://debate.socialism.nl/forum/showthread.php?tid=140637
http://forum.spolokmedikovke.sk/viewtopic.php?f=8&t=1179266
https://talkingpoints.org/subx/showthread.php?tid=65307
http://881.cz/forum.php?mod=viewthread&tid=56198&extra=
http://forum.bandingklub.cz/viewtopic.php?f=32&t=1691479
http://881.cz/forum.php?mod=viewthread&tid=57665&extra=
http://forum.spolokmedikovke.sk/viewtopic.php?f=18&t=1067600
http://forum.spolokmedikovke.sk/viewtopic.php?f=8&t=1068129
http://horsecity.ru/phpBB3/viewtopic.php?f=22&t=271350
https://nauc.info/forums/viewtopic.php?t=22210639
http://horsecity.ru/phpBB3/viewtopic.php?f=13&t=331235
https://talkingpoints.org/subx/showthread.php?tid=36385
http://miweii.com/forum.php?mod=viewthread&tid=19986&extra=
http://forum.spolokmedikovke.sk/viewtopic.php?f=3&t=1159773
http://forum.spolokmedikovke.sk/viewtopic.php?f=4&t=1180702
http://forum3.bandingklub.cz/viewtopic.php?f=15&t=1608208
https://www.ww2.site/forum/viewtopic.php?p=160559#p160559