I watched the tutorials twice, read through all the help, I've even beaten the game a couple of times (on normal difficulty) but I still don't understand how locking glyphs works.
Sometimes I can lock a glyph, and sometimes I can't. Sometimes I can lock a glyph for other people, most times I can't, and even when I do, it doesn't seem to do anything.
I know there is a spell to lock a glyph -- does that mean you can lock 2 glyphs.. assuming the mysterious magical formula for a "regular" lock works?