that's what my character would do

I do not like this excuse. I mean, it could fly the first time you do something that the other players question, but you cannot use it every time. At some point your character must grow. Continuing to use this as an excuse to do off-the-wall stuff will cause the party to lose cohesion, and will eventually break the trust between players. YES, PLAYERS.

As a GM, I cannot completely control this action, it is up to the players to come up with alternative actions that would still fit with their character. If the first instinct is just to do the same thing that is always done (because that is what your character would do), then it is time to expand your character’s tool box. If you are stuck, talk to the GM, they will help you with ideas.

There are definite times that one can use this excuse that will not be detrimental to the group. These are most commonly found in social interactions. Being brash, telling secrets, not sharing enough, becoming recluse after a certain encounter, etc. Allow the time for the other characters to bring it up and ask questions to eventually reveal more in depth backstory. It is exciting to build those relationships between characters, and will draw in others to do the same.

Probably the most important question to ask yourself is why? Why does your character do that? Then think long and hard on some other things. What can get them to do something different? How do others pull you out of the path of self-destruction, or chaos? And…are you, the player, willing to change how your character acts?

All of these questions need to have some answers, nothing elaborate or in depth is needed, but the foundations need to be there. And if the answer to the last question is “no,” you may want to rethink the personality of your character. Hopefully, over some time, you will come to say, “That’s what my character would have done.”