Are we talking small but instense case of current aggro, or a long smoldering aggro leading up to an ultimatium... "it's the game or me!"?
For current aggro, you have to first address the trigger. It is probably too late to take out the trash like she asked but you forgot because you were playing. You will first have to make a more conscience effort. She will often hit you with things that you cannot immeadiately attend to because of things ongoing in the game. Open a browser and type timer 20 minutes. Any timeframe is fine, but it will serve as a reminder to do what was asked. That is generally not enough, and you will have to take her out to eat or something at a place you know she likes/wants to go to, AND it needs to be a place she knows you DON'T LIKE/WANT TO GO TO. Usually during the evening, during prime gaming time. This sacrifice is required to appease the aggro god.
However, if we are taking about the ultimatium, letting her win is not suggested as a long term solution. It will lead to another ultimatium and eventually become a behavior that will cause your divorce/breakup. The key here is to address the underlying issue... she is lonely, feels she is second to the game, and really just wants a little more time in your company.
Skip to the third step if she is already in a compromising mood, otherwise you will have to force a compromise by showing her the alternative. Unfortunately, this will require you to quit (or severaly reduce your time spent) playing for a little bit.
Everquest feeds something in the brain similar to addictive drugs. If you want to go over it, we can start listing all the ways that you are addicted to Everquest (like how you think about it when not playing it). If you quit playing, you WILL show most, if not all, the classic signs of withdrawal. Mostly, this means you will be a bear to be with. Be aware of it, don't let it go overboard, but make sure she is aware of the change in your behavior and its cause.
Second, she has to see what it is she is actually giving up. Generally, she has had free reign of the TV or whatever time filler that she is just as addicted to as you are of Everquest. Usually, it is TV/Streaming, but for some it is social media. Whatever it is, intrude heavily into that part of her life. Watch a show You want to watch, that she does not. Whatever it is, make her feel the crunch. Once again, don't go overboard.
Third, reach an acceptable compromise. If she is feeling cooped up, go out occasionally. Find a TV show that the two of you both like (or at least tolerate pretty well) and watch it together every week. Spend an hour or so a day a one or two days a week after dinner watching a recorded or streaming series. Do the chores you have been slacking on, or just do one that you traditionally do not do occasionally. Mix up some portion of that to show you care.
If she is on the plus side of the crazy/hot scale, you should be able to achieve 90% or more of your old gaming time back fairly quickly. If not, well, you knew this day was coming.