1) DO NOT USE RP AS WISH-FULFILLMENT OR TO VICARIOUSLY GET THE THINGS YOU WISH YOU HAD IN REAL LIFE.
Honestly? This is one of the biggest reasons why I see people blurring the lines between IC/OOC. They really want something in real life, but they can't get it - so they try to live the dream in RP. At that point, they're already mixing IC/OOC because their OOC desires are what ultimately fuels their IC actions. Things suddenly become far more personal and carry far more weight than is appropriate for fantasy pretend-story fun times in a video game.
If you really, really want romance in real life - DO NOT try to get it vicariously in the game only to get super upset when the RP romance doesn't go the way you want.
If you really, really want to be popular or well liked and beloved by everyone in real life - DO NOT make that your sole goal in RP only to get angry when another character doesn't love yours.
The other problem with this is that you have the perfect fantasy in your head of how you would like things to go, but that is YOUR fantasy - not anyone else's. Everyone else has the power to think and act on their own and may make decisions that completely contradict what you want in your perfect scenario. Because you can't force them to be the way you want (unless you're a huge asshat), you just set yourself up for disappointment.
It's also generally (there are of course exceptions to everything) really, REALLY unhealthy to try and use RP to get what you don't have in real life. Fix your real life first - then play the game.
2) Everyone's already mentioned communication. I'm just putting it here to stress how important it is even more. This is doubly true if you're playing a villain. I know a lot of people are super strict about no OOC in their RP because it ruins immersion, but I personally feel like I HAVE to have it to make sure that not only are we on the same page, but to show that I am a friendly, kind person even if my character is a villainous jerk or a grumpy asshole.
When all someone sees of you is your IC jerkface villain, it can be easy for even the best-intentioned person to kinda slip up and wonder if you are also a jerk OOC, but not if you show that you're a good, friendly player behind the character.
3) Lastly, think of your characters as characters for a literal book you are writing - not characters you am inserting yourself into or becoming. RP is like a giant book written by numerous authors. Or like another analogy, a comic series where different parts of the comic universe are written by different people. You don't get pissed at another author for having a villainous character in their story/comic. The author is not their characters. YOU are not your character. Your character is just a creation for the story you're writing with everyone else.
When you think of it in this light, suddenly a lot of bad and horrible things that could happen to your character are just terrible, but AWESOME things that make for a really fantastic and dramatic story.
A painful betrayal might suck for the character, but it can be excellent for building a deeper narrative or creating more character development! Having a hated rival might suck for the character, but it's great for building up a story between another player! This is why I love all kinds of moments from the soft fuzzy happy stuff to the heart-wrenching, painful, tragic events because it's exactly like all of the awesome FEELS you get from a great book.
Honestly? This is one of the biggest reasons why I see people blurring the lines between IC/OOC. They really want something in real life, but they can't get it - so they try to live the dream in RP. At that point, they're already mixing IC/OOC because their OOC desires are what ultimately fuels their IC actions. Things suddenly become far more personal and carry far more weight than is appropriate for fantasy pretend-story fun times in a video game.
If you really, really want romance in real life - DO NOT try to get it vicariously in the game only to get super upset when the RP romance doesn't go the way you want.
If you really, really want to be popular or well liked and beloved by everyone in real life - DO NOT make that your sole goal in RP only to get angry when another character doesn't love yours.
The other problem with this is that you have the perfect fantasy in your head of how you would like things to go, but that is YOUR fantasy - not anyone else's. Everyone else has the power to think and act on their own and may make decisions that completely contradict what you want in your perfect scenario. Because you can't force them to be the way you want (unless you're a huge asshat), you just set yourself up for disappointment.
It's also generally (there are of course exceptions to everything) really, REALLY unhealthy to try and use RP to get what you don't have in real life. Fix your real life first - then play the game.
2) Everyone's already mentioned communication. I'm just putting it here to stress how important it is even more. This is doubly true if you're playing a villain. I know a lot of people are super strict about no OOC in their RP because it ruins immersion, but I personally feel like I HAVE to have it to make sure that not only are we on the same page, but to show that I am a friendly, kind person even if my character is a villainous jerk or a grumpy asshole.
When all someone sees of you is your IC jerkface villain, it can be easy for even the best-intentioned person to kinda slip up and wonder if you are also a jerk OOC, but not if you show that you're a good, friendly player behind the character.
3) Lastly, think of your characters as characters for a literal book you are writing - not characters you am inserting yourself into or becoming. RP is like a giant book written by numerous authors. Or like another analogy, a comic series where different parts of the comic universe are written by different people. You don't get pissed at another author for having a villainous character in their story/comic. The author is not their characters. YOU are not your character. Your character is just a creation for the story you're writing with everyone else.
When you think of it in this light, suddenly a lot of bad and horrible things that could happen to your character are just terrible, but AWESOME things that make for a really fantastic and dramatic story.
A painful betrayal might suck for the character, but it can be excellent for building a deeper narrative or creating more character development! Having a hated rival might suck for the character, but it's great for building up a story between another player! This is why I love all kinds of moments from the soft fuzzy happy stuff to the heart-wrenching, painful, tragic events because it's exactly like all of the awesome FEELS you get from a great book.
