M (mercury, phosphorus, and powdered diamond and opal worth 1,000 sp, consumed)

As you spend 1 minute to cast this spell, you inscribe a harmful glyph either on a surface (such as a section of floor, a wall, or a table) or within an object that can be closed to conceal the glyph (such as a book, a scroll, or a treasure chest). If you choose a surface, the glyph can cover an area of the surface no larger than 2 meters in diameter. If you choose an object, that object must remain in its place; if the object is moved more than 2 meters from where you cast this spell, the glyph is broken, and the spell ends without being triggered.

The glyph is nearly invisible, requiring a Perception check against your spell save Difficulty to find it.

You decide what triggers the glyph when you cast the spell. For glyphs inscribed on a surface, the most typical triggers include touching or stepping on the glyph, removing another object covering it, approaching within a certain distance of it, or manipulating the object that holds it. For glyphs inscribed within an object, the most common triggers are opening the object, approaching within a certain distance of it, or seeing or reading the glyph.

You can further refine the trigger so the spell is activated only under certain circumstances or according to a creature’s physical characteristics (such as height or weight), or physical kind (for example, the ward could be set to affect hags or shapechangers). You can also specify creatures that don’t trigger the glyph, such as those who say a certain password.

Once triggered, the glyph glows, filling a sphere twice as big as normal with dim light for 10 minutes, after which time the spell ends. Each creature in the area when the glyph activates must succeed on a Fortitude saving throw or be stunned for 1 minute.

A creature must also make this saving throw when it enters the spell’s area for the first time on a turn or starts its turn there.