I posted this over on the 5e forum but I'll post it where it belongs. Setting creatures ER to resist bludgeoning and then using a Warhammer to beat on said monster,which I've named Beat Down Rick, doesn't seem to do anything. The damage isn't mitigated. I tried to set slashing to immune and used a longsword on poor old Rick and man was he surprised when inside of taking ZERO damage he took the full blow of sword for 11 damage! Not sure if it's a known issue but I wanted to put it out there.