For glyphs inscribed on a surface, the most typical triggers include touching or standing on the glyph, removing another object covering the glyph, approaching within a certain distance of the glyph, or manipulating the object on which the glyph is inscribed. You decide what triggers the glyph when you cast the spell. The glyph is nearly invisible and requires a successful Intelligence ( Investigation) check against your spell save DC to be found. If the surface or object is moved more than 10 feet from where you cast this spell, the glyph is broken, and the spell ends without being triggered.
The glyph can cover an area no larger than 10 feet in diameter. You inscribe it either on a surface (such as a table or a section of floor or wall) or within an object that can be closed (such as a book, a scroll, or a treasure chest) to conceal the glyph. When you cast this spell, you inscribe a glyph that later unleashes a magical effect. Phandelver and Below: The Shattered Obelisk Mordenkainen Presents: Monsters of the Multiverse