Treating low-CR creatures as traps

As your party advances in level, certain monsters no longer pose much of a threat. If a combat encounter would be so lopsided that the enemies have no chance of winning, should you roll initiative and run a full battle?

Imagine a level 10 party facing the following monsters: 

• A skeleton lying near a treasure chest
• A dust mephit springing out of a desk
• A violet fungus lashing out at anyone who enters a cave

These types of encounters make sense for the situation, and shouldn’t go away just because the party leveled up. With these types of low-risk encounters, instead of running a full combat, you can treat the monster like a trap. Tell the player what their character would see or hear, let them narrate how they would handle the situation, and then have them make the appropriate roll. 

For example:

• If the character would try to jump out of the way or raise their shield, have them make a Dex save. 
• If the character would try to kill the creature before it attacks them, have the character make an attack roll.

If the character makes their roll, they are able to avoid any damage. Otherwise, the monster lands an attack before being destroyed by the high level party. 

This has several advantages:

• You can include creatures that make sense for the environment and situation without slowing the game down.
• The players feel powerful when they can swiftly handle threats that previously required a full combat.
• There is still a chance the character suffers minor damage from the “trap,” encouraging the party to proceed cautiously and thoughtfully.