Not only with the Wrath of the Lich King expansion but as early as with patch 3.0 Blizzard has introduced a new profession, inscription, to World of Warcraft. With this profession one is able to create glyphs, little scroll that change they way spells and abilities work by improving their damage and changing their mechanics. Every player has 3 major and 3 minor glyph slots at level 80, making for a total of 6 glyph slots. Minor glyphs reduce the reagent requirement for a spell or cause a cosmetic change to the spell effect. Major glyphs often provide a major bonus for a skill or ability. Glyphs are created by a scribe who needs ink and parchment for their creation. Parchment is bought at a merchant while ink is milled from herbs. The level of the ink depends on the herb's level, and most of the end game glyphs require herbs from Northrend to be created.

A Shadow Priest's first choice will be the Glyph of Shadow, increasing his spellpower by 10% of his spirit whenever he scores a critical hit, making spirit an even more valuable stat. The Glyph of Shadow Word Pain will increase his Mindflay ticks, so it makes for a nice second choice. Holy and Discipline Priests have lots of glyphs to chose from to improve several of their healing spells. Circle of healing is able to hit a sixth target with the right glyph or Prayer of Healing can leave a heal over time effect on the affected targets. Flash heal and Power Word: Shield can be improved with glyphs as well.