Scale a Monster to Any CR
Pick a monster and the CR you want, then open it in the Forge. The Forge rates the monster from its own numbers, which often lands a step or more from the CR the SRD prints, and shows its rating beside the printed one. Press Scale and it moves its hit points, armor class, attacks, and save DCs from its own rating toward the CR you picked, keeping how it fights. Nothing moves until you press it. The CR on the statblock is yours to set; scaling never changes it.
New numbers are half the job.
Save it and it waits in the app’s Library on this browser, ready to fight at the CR you set.
Two ratings
The Book CR is the DMG’s table shifted to where the books usually rate monsters like it. The DFC CR adds what each trait is worth, with one stated reason per trait. Scaling aims at the DFC CR, which is why a monster can need raising even when the CR you asked for sits under the one the SRD prints; when a press would do that, the Forge says so first.
What scaling keeps
The monster’s entries, how many times it attacks, and its spells’ own dice. If it hits harder than it lasts before you scale it, it still does after, even when a number can’t move far enough. When one can’t, the report that follows the press offers a second one, “Let hit points and armor class make up the rest” or “Let damage and to-hit make up the rest”, and says what it would move. Scaling changes numbers, and the bonus beside a damage roll, never the sentence around them.
What it can’t move
Numbers in sentences the Forge can’t open as fields, a book caster’s spellcasting line, and armor class that comes from armor it wears. After a press, the report lists every number it changed, every one it left, and, for a spellcaster whose damage is all spells, how far short of your CR it stopped.