When setting the scene, the GM should think of interesting and dynamic environmental features that can constrain the action or provide opportunities to change the situation by using them. Three to five details are more than enough. Use these categories as a guide:

• Tone, mood, or weather—darkness, lightning, and howling winds
• Impediments to movement—connected by ladders, covered in slime, and filled with smoke
• Cover and obstructions—vehicles, pillars, and crates
• Dangerous features—crates of TNT, barrels of oil, and eldritch artifacts crackling with electricity
• Usable objects—improvised weapons, statues or bookshelves to knock over, and doors to be barred

Anyone can invoke and compel these aspects, so remember to take them into account when you wrestle that cultist to the ground amid the Caustic Slime Covering Everything.

More situation aspects can be written down as the scene plays out. If it makes sense that there are Deep Shadows in the recesses of the catacombs, go ahead and write that down when a player asks if there are any shadows they can use to hide. Other aspects come into play because characters use the create an advantage action. Things like Flames Everywhere! don’t just happen without character action. Well. Usually.