Resistance items don't stack?

[Daynarr]

Originally posted by mivayan:
50% resistance items dont stack. Other combinations stack, like charcoal shield (50%) + fire restitance ring (100%) + barkskin amulet ( -50%) results in 125%.

Is it me or is something wrong with this math?

Barkskin amulet gives -25 not -50 (like barkskin, protection or mass protection spells) so your total is correct.