What is the CR of a 3rd level character?

Encounter Difficulty

What CR is good for my party?

In planning encounters recognize that a “fresh” party can generally handle a creature 2 CRs above their adjusted average party level. Three CRs above and you’re pushing. At the 4+ adjusted average level range, you’re looking at a good chance of somebody dying.

How do you fight the Balor?

Balor is immune to much of your hits with melee weapons. You should maintain a safe distance and make use of your ranged weapons and abilities. Balor may be defeated with Mark of Death and Focus of the Nornir. If Balor uses the Aerial Dive, Flaming Sword, or Cyclops Laser skills, make sure you can dodge easily.

Can a party of three level 10 characters defeat an 18th level archmage?

This is extremely situational. In a neutral arena, level ground, encounter without forethought, the party of 3 10th levels will most likely defeat the 18th level 12CR archmage pretty quickly, if they have decent tactics and mobility. Numbers matter a lot in this game, due to the action economy.

What should the CR be for a CR12 monster?

IE: a CR12 monster is expecting to go up against an normal size (4-5 characters) party of level 12 players. So the “CR” of a player is essentially 1/4th of the party level, all things being equal, the CR of a PC should be 1/4th of their level.

How much XP does an archmage give you?

An Archmage yields 8400 XP, and DMG 82 states that for 3 level 10 characters, the XP threshold for a “deadly” encounter is 8400 XP. That means the Archmage is barely on the edge of being “deadly,” which in my experience usually means “one or two PCs actually take some damage”.

How much XP would a party of three level 10 characters get?

That means the Archmage is barely on the edge of being “deadly,” which in my experience usually means “one or two PCs actually take some damage”. In fact, the daily adventure XP budget for 3 level 10 characters is 27,000 XP, or basically three Archmage encounters before a long rest.