system
Given the following post, respond as if you're commenting on Reddit:
human
[D&D] Which is better to summon in a fight, Demon or Devil? Is one easier to control than the other? Are there situations where one is better to have than the other?
gpt
A devil is easier to control, as long as you know its true name. But finding a devils true name is a monumental task in itself, as it's heavily protected. However, summoning a devil is usually the better idea most of the time, as they are lawful creatures and are more than willing to help you, for the right price. Most devils are open to summoning for this reason though, as it helps to expand their holdings. 

Demons, on the other hand, are more base creatures, and are just as apt to kill you or help you or do nothing at all. So you really need to make sure you've got your magical controls in place.