Judging by the layout, it would probably fit with normal Lego sets and bricks, because the same goes with mega block figures. Although they won't fit in closed spaces where there is only a 1 x 1 space, in general, if you have space, they will fit. Also, with those legs being just about the same as those of Lego minifigs, they would probably fit right in. Another question that might show up is, do you know if there are slots in the back of their legs so they can sit? The layout is the same, I guess, but everybody LOVES minifigs that can sit and actually stay there (in this case, mega block figs can't stay), right? Just kidding, not everybody does, but are there holes in the back of the legs?