So sickened and frightened don't stack right?

[CorvusMask]

They both give status penalty, so only highest one of two is applied right?

Also on sidenote, does "damage" count as check aka do frightened and sickened reduce damage as well?

[Franz Lunzer]

Check
Unless you do damage with a d20, it isn't a check. ;)
To be clear: Even if you somehow did roll a d20 for damage, it still isn't a check, there is no DC to compare against, no degree of success...

Yeah, status penalties do not stack. (There are very few things that stack in 2e)

[Ubertron_X]

Well, there goes my Frightening Stinking Cloud of Clumsy Enfeeblement spell research... :P

[CorvusMask]

Thank you :D Had to check I understood stuff right