Well I used to have one (Before an over protective parent chucked it in the garbage) it was definitely 1 sided. When you flip the sucker around, the BACK of the blade comes in contact with the BACK of the wrist.. so it would be VERY bad if t was 2 sided! Some do look 2 sided, but only near the front of the blade is 2 sided. I woudl say on a 4 " blade, maybe only 1 " of it is 2 sided. And it looks like a dagger style from what I remember.