What is the second sublayer of layer 7 when dealing with continuous effects (layer 7b)?

The second sublayer of layer 7 pertains to effects that set power and/or toughness to a specific number or value. In the context of continuous effects within Magic: The Gathering, layer 7 is specifically concerned with how creature characteristics such as power and toughness are modified.

Layer 7a deals with the effects that change a creature's base power and toughness. Once those base values are established, layer 7b comes into play and handles any effects that explicitly set the creature's power or toughness to fixed numbers irrespective of any other modifications that might apply. This means if a creature's toughness is set to, say, 3, it will override any previous values or adjustments that apply to it up to that point, effectively establishing a new, fixed point for that characteristic.

Understanding this part of layer 7 is crucial for correctly resolving how creatures interact on the battlefield when multiple effects may be attempting to modify them. The foundational mechanics of the game are predicated on these rules about how characteristics are determined, and recognizing the distinction in layers is essential for effective gameplay and judging.