What is CR?

The CR in a D&D creatures stat block stands for Challenge Rating. Although it’s the perfect way to choose interesting enemies, the Challenge Rating is only a guideline. It’s an estimate of which level a balanced party of 4 players should be to be able to handle that single enemy. All based on it’s health, actions and reactions.

Setting the difficulty

When building combat encounters you don’t need the CR. As you can see in the DMG at p82 there is an XP threshold based on the party’s level and the difficulty you are aiming for. Choose your monsters, add up their XP value and apply the relevant multiplier bases on number of enemies. Now you have an estimate on how well the party will do in that encounter. As long as you also take the following variables into account.

What can affect CR

– Teams balancing (How to balance a party) – Not having a diverse party creates weaknesses (and strengths) that can be exploited. Either the party needs to be fine with having weaknesses or the DM needs to be aware and account for them or risk a TPK.
– Magic items – Every DM varies in the amount of magic or powerful items they give out to their players. A few low level items won’t make a difference, but they add up which gives the party the power they would normally only have at later levels. Handing out low level items still rewards them without overpowering them (Low level magic items).
– Environment (Create an active environment) – This can work in either direction. Sometimes the players walk into a trap where they are suddenly surrounded by ranged archers that are in 3/4 cover and sometimes the wizard can push 5 goblins off of a cliff with a single spell.

Adjusting the CR

But what if you really want to use kobolds at later levels or a dragon early on? Or what if halfway through a fight you find out the battle is too easy or hard? You are the Dungeon Master so you decide what happens! To make the fights harder you could give the enemies more HP, let more enemies join the fight or up their stats so they hit harder. Same goes the other way. If you need the fight to be easier you could weaken the enemies, make some of them flee or end the fight outright by making a chasm appear in between the party and the enemies. Just make sure it doesn’t feel too forced, everyone at the table keeps having fun and the battle is interesting.