Due to events that occurred during my games I had to come up with a DC to break a door. The DMG has some details on this but its max DC was 28 vs str check on an iron door. After doing the normal made up DC the player still got through this door (an adamantine door 2 inch thick and yes it fit the area)
This got me thinking that the table based DC was in a sense... not complete. So I came up with a mathematical check and rebalance of the DC.
New check 10+hardness+4/in thick
This makes a 2 inch thick adamantine door a DC 38.
Mind you this is literally to break the door not just pop it open.
Was wondering what others would think on this