Many cards in this set reward you for improving your creatures by referring to "modified" creatures. A creature you control is considered modified if it has at least one counter on it, if it's equipped, or if it's enchanted by an Aura you control.

Every Saga has three chapters, represented by the I, II, and III symbols. Each chapter also has a corresponding effect. For The Flame of Keld, we see that the effect of chapter I is "Discard your hand." The story gets better, I promise. Some Sagas have the same effect for multiple chapters. Instead of that effect being listed more than once, you'll notice that the chapter symbols are just grouped together with the appropriate effect.

Each Vehicle begins as simply an artifact. That is, a tantalizingly drivable artifact. Most Vehicles have the crew ability, which turns it into an artifact creature until end of turn. To activate a crew ability, you tap a number of other untapped creatures you control with total power greater than or equal to the number after crew. The crew ability doesn't use the symbol, so you can tap an untapped creature you control that just came under your control to crew a Vehicle. While a Vehicle can't be used to crew itself, a Vehicle that's a creature can be tapped to crew another Vehicle.

Shrine is an enchantment type that has no inherent rules meaning, but each Shrine gets better and better as you control more and more Shrines.