Certain knife styles or profiles will automatically be given the 'weapon' status, some simply because there really is no other practical use for such a blade. Some states and jurisdictions ban certain styles, usually related to the ease of deployment but also by blade profile. But the definition of what is a weapon and what is not is not something that is clearly defined. But like the classic SC Justices' definition of pornography, most juries and judges will use the same definition : "I cannot clearly define it. But I know it when I see it." As an example, try convincing a judge or jury that your were carrying concealed the blade below only as an EDC user. Doesnt help much that the knife is named 'Shasta McNasty'. I think it is obvious what the outcome would be once the jury saw the knife in court and was told it is called Shasta McNasty. At best, the jury thinks your just a mall ninja playing billy bada$$ and lets you off with a fine and community service. At worse, you're looking at felony and 2-5 years for concealed carry of a deadly weapon. Some other blades would be borderline calls. It's best to not overdo it and its best to not announce to the world what you choose to carry around.