You can't climb anything that isn't a ladder in
Dark Souls. This can lead to ridiculous scenarios where you're blocked from moving by a ledge that only goes up to your
knees. Probably the worst case was in
Dark Souls II, where your main objective for the first half of the game is to get to Drangleic castle, but you are blocked from doing so by a pile of rubble that a child could easily climb over. To get around it, you need to run all over the game world to find and slay four legendary beings of immense power and acquire their souls, then head up a barely noticeable dirt path next to the rubble and use those souls to open a tiny building called the Shrine of Winter, which has an exit on the other side, allowing you to finally continue on past the rubble to Drangleic Castle. This raises the question of why the rubble even needed to exist in the game at all when the developers could have just put the Shrine of Winter where the rubble was and left it at that.