One of my players wanted to create a character with dissociative personality disorder.
We drafted the following rules: He has multiple character sheets, but one is the main one. The main one contains all abilities' score, HP, physical characteristics, armor, weapons, items. The others have only the class/background/alignment/personality specifics in them.
Now to the rules deciding how to change personality: Everytime he rolls a 1 in a d20 he changes. Everytime his HP is reduced to 0 he changes. Situationally, if the current personality is too stressed out, he must pass a Insight check otherwise he changes.
When he changes, I let him decide which personality will take over now.
We're still testing, but it seems balanced and interesting so far.
My take on that would be to further evaluate the nature of his disorder and his personalities. Is it like a good/evil flip or more of a law/chaos type flip? Or is it solely eccentricity that changes? If so i'd look into Multiclass mechanics to supplement the personalities. Having a fighter who can flip into a wizard can change dynamics a lot, i'd take a closer look into the class mechanics and maybe find ones that are more parallel or fitting to his story. Or keep the same class and change their archetypes. A Wizard may switch schools of magic, a cleric may worship two deities, a Thief may become a ruthless Assassin, a strong fighter becomes a tactical battlemaster, a Druid changes into a personality too akin to his wild shape and is stuck in wildshape, Paladin swears two different oaths, A Bard who cant make up his mind on what instrument or stories he likes best.
I would have the chance roll be every short/long rest. Essentially he could wake up and be a different person.
Rollback Post to RevisionRollBack
“The harder the world, the fiercer the honour.” ― Steven Erikson, Memories of Ice
I agree, the difference between personalities should be limited somehow. The character backstory have to explain why he developed both personalities and why they are what they are.
As for the roll in short/long rest, that could be interesting. Especially if everytime he rolls to change, I narrate a really bad dream (EDIT: or a dream involving the personality that will take over next morning) his character had during his sleep.
Encourage some sort of secrecy, so the party as a whole has no idea what his character will do. Entertain the idea of passing secret notes/text messages between you and the player so only you two know what his personality/capabilities are at any given time.
Rollback Post to RevisionRollBack
“The harder the world, the fiercer the honour.” ― Steven Erikson, Memories of Ice
perhaps players dealing with a party member who has this would need to make a int or wisdom check to tell if the personality has changed given a reason to suspect a change. Also the personalities might have to make apposed wisdom checks to see if the one in control looses control. depending on the personality events, phrases, and or damages could also cause a need for this check between the personalities.
I came up with something similar but my character was possessed by a lesser demon of a sort and would and could switch, the twist was that switching was like a sort of lycanthropy both the humanoid and demon both having separate stats and forms. Perhaps a demon was a poor fit for this concept but im sure someone can think how to make this concept work.
Sounds like a fun and interesting character to play! My suggestion, when the time comes to change personality, use a dice to determine which personality takes over. That way your player has no choice in who they want to step in. A person with this disorder doesn't choose who comes out next.
In a game I was playing we had a character like this. The player and the DM decided that at the start of every day the player would roll a D20. Under 10 he was the first personality. Over 10 he was the other.
It made the game interesting because they had different skill sets..and it often made for hilarity when he failed a roll..that he would have passed with flying colors if he was of the opposite personality.
1) Because actual cases of severe mental disorder are not fun, but terrifying and unsettling.
2) Because actual cases of severe mental disorder are not fun, but terrifying and unsettling.
3) This kind of thing isn't good for a player in the party. Part of being in a "party" is knowing when to let everyone else have spotlight, and this situation becomes the spotlight. I doubt the the other players will really have fun being in the same party as dealing with "randomness" from a party member instead of the environment. It will be funny at first but it will quickly wear thin.
4) Because of the above, if it's to be implemented I see it as a GM's NPC toolbox. Something to run in a horror game, to unsettle the players.
You should also be very careful about balancing this. I just talked a friend through doing a similar thing, and here's what I told him; if you have multiple personalities, each of which is a totally different class that is the same level as the other PCs, then that character will by nature be OP. This is still the case if all you switch is archetype. It doesn't matter that the PC would not be the one to choose when to switch, the fact is that they will have objectively more options potentially available to them at any time.
The concern here is that maybe doing this would feel unfair to the rest of the players, who are limited to one class or multiclass, while this PC seemingly is not limited in that way. I always love the concept, but it's almost impossible to pull off without being either over or under powered, in my opinion.
I have a player requesting a multiple personality disorder, but as a result from capture and torture, a demonic soul has been placed in this characters body. Now the question of progression comes up. so if I allow a switch over character,(and I do enjoy the idea very much). Do both personalities level up? are we talking a character that is essentially level 10 but is 2 level 10 characters? or when leveling happens, does the personality in control gain the level? Unless they level up evenly, I do not see a way for the character to be viable, and if they level up at the same time, the character seems to be extremely over powered. for one monitoring the spell slots expended, seems to be a task in general, let alone all of the other issues that may/will arise, (are there different mental scores? monitoring passive perception, saving throws and ability checks, static buffs as one character, (do they dissipate if a change over happens). I really want to make this happen, but don't want to give an unfair advantage.
If I were to allow this sort of character, then the mechanical effects of a change would be extremely limited - everything should be focused on role-play differences. Multiple classes, different spells, even different proficiencies are all impossible to balance, and by definition overshadow other players. At most I would have each personality get its own alignment, bond/ideal/flaw, and maybe a language (since the mechanical benefits of that are pretty small). From there it would be up to the player to role-play the differences.
In my campaign, we have a war-forged player character tasked with protecting a special artifact. However, his character has since been uploaded into the artifact (which happens to be a gem akin to the ones in Steven Universe) alongside a flawed AI that prioritizes killing all hostiles.
So, there is now this extremely conflicted character, who's primary directive is to defend it's body (the artifact), and the other half wants nothing more than to put itself in danger no matter how challenging the task at hand.
The switch happens whenever someone says their names (Omega or Epsilon). Interestingly enough, one of our other players (who happens to be an Illithid), chose to take advantage of this-- they said Epsilon's name and told him that a house (with a perfectly innocent family inside) had hostiles in it. He immediately killed everyone inside and the Illithid character ate their brains.
Multiple Personality Disorder a little bit more complicated than that. I mean as in, every personality would have their own ability scores.
Each person can be different in so many things. The brain is extremely powerful. Some personalities are wiser and have more intelligence, especially older personalities, and younger personalities would have lower wisdom. Its the same with any real life ability. In real life, thats how it would be. So if you would like to keep it realistic, having different modifiers makes a lot of sense, keeping it the same wouldn't make sense.
A person with the disorder doesn't choose you're right. The situation does. Normally people with Multiple Personality Disorder got the disorder from being being put into traumatic situations. This person copes by creating personalities that deal with this situation. So when a situation like that, or close to it, arises that personality will come out. So for example, if a person was physically abused at a young age and a personality emerged that help that person fight back, it would make sense that that personality would come out when fighting.
Every case is different, but persoanilties usually are created to deal with certain situations. If a personality that was created for, lets say, relationships, and they randomly came out during fighting that wouldn't make sense. The personality that was created for fighting, or the like, wouldn't even be doing what it was created for.
What if you had a situation where a player creates a Dr. Jekyll & Mr Hyde changeling type character. Using a duel class, they uncontrollable switch between the personality, predominately of Dr. Jekyll, to a Mr. Hyde type personality? For instance, say the player's character was a Bard-Barbarian, who stayed in a fully Bard mindset, with abilities to basically rage. They could be playing music, doing their bard thing, get excited and roll a d20, that forces the player to use a rage, if available as a bonus action, and turn into a barbarian for the attack. As a changeling, the question come in if allowing the player to switch between two different "masks" would be allowed as a reflex-type of action. Is this too OP for the game?
Chances are, yes. Any time you have a character that has access to *more* options than another character, even if it's not fully controlled when they make the switch, it's going to be OP. It will also most likely make the other players annoyed, just because you are effectively playing two full classes while they are stuck with either a single class or multiclass.
That being said, lots of games run homebrew material and intentionally make PCs overpowered in order to have more fun with it. Talk to your DM about the situation. In a "standard" game I'd say don't do it. But DND is rarely standard.
Rollback Post to RevisionRollBack
I know what you're thinking: "In that flurry of blows, did he use all his ki points, or save one?" Well, are ya feeling lucky, punk?
All the DM has to do is debuff your experience therefore your levels, because the other personality experienced that situation/conflict. There are plenty of ways of balancing it. Another thing you could do is just not make the split personality have a different class. This fixes a lot of the problems I would see with this build.
I've given this some thought and I wanted to see what others thought about this as well:
Split Persona Feat:
Taking the Split Persona Feat would mean you have two different personalities that should start off conflicting and hopefully learn how to exist with this type of life. There is no cure, it is only learning how to cope and handle. You are only able to take this feat at Lvl 5 and up. This feat also progresses as you level up your main character. Once you take this feat there are levels to how it effects your character. At the beginning, there is no control, its happens in stressful situations and every start of your round in a battle. It is a flip of a coin whether or not you change. With the levels progressing, so does your chances to adapt, and learn to live with this disability. This is NOT an easier way to multi-class, this is a disability that you have to learn how to live with and take control of what it is to you. Depending on your main character, your split or secondary character must be of a different class and different alignment than the original. Example: If your main is a Goliath Barbarian that is Lawful Good, then the secondary character/personality must be at class that is counter to a barbarian, such as a Cleric, Bard, Sorcerer, Warlock, or Wizard. The alignment can still be Lawful but must change to Neutral or Evil . Your secondary could even believe he is a gnome in a Goliath's body.
To prevent any double stacking, each personality has their own stats. So when you first select this feat, work with your DM to determine the secondary character and work out how it effects the main characters story. The secondary personality will have their own base stats and cannot override the mains stats and vice versa. This will prevent rolling a save/check using a different personality stats. The only stat that will cross over is the constitution, the higher of the two shall be used for both characters. Additional or other feats cannot affect this feat. This and 1 other feat may be listed on any additional personalities. Example: A barbarian as a secondary personality must have this feat and have the option to choose 1 other feat on personality upon leveling. No more additional feats may be added there after on personality.
If either main or additional personalities falls unconscious, character reverts back to main.
(Side note: a heart monitor may be worn by player to help determine raise in heart rate to determine stressful situations)
Start of Feat:
Stressful Situation(s) / Start of Every Battle Round
Call either Heads or tails and flip a coin. If you side you called lands up, then the flip is successful and you do not change. If fails, you change into secondary personality.
Some physicality may change based on switch. Example: Goliaths have a CON+1 and STR+2, these stats are lost on switch to Gnome who has a INT+2. The Goliath will shrink in size slightly, but will not become the size of a gnome.
After living with 3 levels of Feat:
Stressful Situation(s) / Start of Every Battle Round
Choose 1 option to continue with:
1. Roll a D20, 11 or higher is successful, anything else is failure. Success deems no change, a failure is a switch.
or
2. Add a third personality to add to your Personality pool. 1D4 is rolled where 1 is the main, 2 is the secondary, 3 is the third personality, and 4 is a reroll.
After living with 5 levels of Feat:
Stressful Situation(s) / Choice
Change is based on previous option chosen:
If option 1 is chosen - anytime a Constitution Check is asked by the DM or requested by the player. With a DC of 10, each success increases DC by 1 and a failure resets to base DC.
If option 2 is chosen - when a Constitution check is asked by the DM, roll w/ advantage a 1D4 to determine personality. If there is a tie, roll until personality is determined (max 6 rolls).
This is just a rough draft of what a split personality feat may look like and I'm always looking for way to improve or develop something like this to play. Thoughts and critiques are most welcomed and appreciated.
Split Persona Feat: Taking the Split Persona Feat would mean you have two different personalities that should start off conflicting and hopefully learn how to exist with this type of life. There is no cure, it is only learning how to cope and handle. You are only able to take this feat at Lvl 5 and up. This feat also progresses as you level up your main character. Once you take this feat there are levels to how it effects your character. At the beginning, there is no control, its happens in stressful situations and every start of your round in a battle. It is a flip of a coin whether or not you change. With the levels progressing, so does your chances to adapt, and learn to live with this disability. This is NOT an easier way to multi-class, this is a disability that you have to learn how to live with and take control of what it is to you. Depending on your main character, your split or secondary character must be of a different class and different alignment than the original. Example: If your main is a Goliath Barbarian that is Lawful Good, then the secondary character/personality must be at class that is counter to a barbarian, such as a Cleric, Bard, Sorcerer, Warlock, or Wizard. The alignment can still be Lawful but must change to Neutral or Evil . Your secondary could even believe he is a gnome in a Goliath's body. To prevent any double stacking, each personality has their own stats. So when you first select this feat, work with your DM to determine the secondary character and work out how it effects the main characters story. The secondary personality will have their own base stats and cannot override the mains stats and vice versa. This will prevent rolling a save/check using a different personality stats. The only stat that will cross over is the constitution, the higher of the two shall be used for both characters. Additional or other feats cannot affect this feat. This and 1 other feat may be listed on any additional personalities. Example: A barbarian as a secondary personality must have this feat and have the option to choose 1 other feat on personality upon leveling. No more additional feats may be added there after on personality. If either main or additional personalities falls unconscious, character reverts back to main. (Side note: a heart monitor may be worn by player to help determine raise in heart rate to determine stressful situations) Start of Feat: Stressful Situation(s) / Start of Every Battle Round Call either Heads or tails and flip a coin. If you side you called lands up, then the flip is successful and you do not change. If fails, you change into secondary personality. Some physicality may change based on switch. Example: Goliaths have a CON+1 and STR+2, these stats are lost on switch to Gnome who has a INT+2. The Goliath will shrink in size slightly, but will not become the size of a gnome. After living with 3 levels of Feat: Stressful Situation(s) / Start of Every Battle Round Choose 1 option to continue with: 1. Roll a D20, 11 or higher is successful, anything else is failure. Success deems no change, a failure is a switch. or 2. Add a third personality to add to your Personality pool. 1D4 is rolled where 1 is the main, 2 is the secondary, 3 is the third personality, and 4 is a reroll. After living with 5 levels of Feat: Stressful Situation(s) / Choice Change is based on previous option chosen: If option 1 is chosen - anytime a Constitution Check is asked by the DM or requested by the player. With a DC of 10, each success increases DC by 1 and a failure resets to base DC. If option 2 is chosen - when a Constitution check is asked by the DM, roll w/ advantage a 1D4 to determine personality. If there is a tie, roll until personality is determined (max 6 rolls).
I would have him roll percentile to see what personality comes out. It does sound that it's pretty severe though lol they are going to have a blast roleplaying lol.
Rollback Post to RevisionRollBack
-Sol
To post a comment, please login or register a new account.
One of my players wanted to create a character with dissociative personality disorder.
We drafted the following rules: He has multiple character sheets, but one is the main one. The main one contains all abilities' score, HP, physical characteristics, armor, weapons, items. The others have only the class/background/alignment/personality specifics in them.
Now to the rules deciding how to change personality:
Everytime he rolls a 1 in a d20 he changes.
Everytime his HP is reduced to 0 he changes.
Situationally, if the current personality is too stressed out, he must pass a Insight check otherwise he changes.
When he changes, I let him decide which personality will take over now.
We're still testing, but it seems balanced and interesting so far.
Let me hear your thoughts, ma fellow GMs.
My take on that would be to further evaluate the nature of his disorder and his personalities. Is it like a good/evil flip or more of a law/chaos type flip? Or is it solely eccentricity that changes? If so i'd look into Multiclass mechanics to supplement the personalities. Having a fighter who can flip into a wizard can change dynamics a lot, i'd take a closer look into the class mechanics and maybe find ones that are more parallel or fitting to his story. Or keep the same class and change their archetypes. A Wizard may switch schools of magic, a cleric may worship two deities, a Thief may become a ruthless Assassin, a strong fighter becomes a tactical battlemaster, a Druid changes into a personality too akin to his wild shape and is stuck in wildshape, Paladin swears two different oaths, A Bard who cant make up his mind on what instrument or stories he likes best.
I would have the chance roll be every short/long rest. Essentially he could wake up and be a different person.
― Steven Erikson, Memories of Ice
I agree, the difference between personalities should be limited somehow. The character backstory have to explain why he developed both personalities and why they are what they are.
As for the roll in short/long rest, that could be interesting. Especially if everytime he rolls to change, I narrate a really bad dream (EDIT: or a dream involving the personality that will take over next morning) his character had during his sleep.
Good idea!
Encourage some sort of secrecy, so the party as a whole has no idea what his character will do. Entertain the idea of passing secret notes/text messages between you and the player so only you two know what his personality/capabilities are at any given time.
― Steven Erikson, Memories of Ice
perhaps players dealing with a party member who has this would need to make a int or wisdom check to tell if the personality has changed given a reason to suspect a change. Also the personalities might have to make apposed wisdom checks to see if the one in control looses control. depending on the personality events, phrases, and or damages could also cause a need for this check between the personalities.
I came up with something similar but my character was possessed by a lesser demon of a sort and would and could switch, the twist was that switching was like a sort of lycanthropy both the humanoid and demon both having separate stats and forms. Perhaps a demon was a poor fit for this concept but im sure someone can think how to make this concept work.
Sounds like a fun and interesting character to play! My suggestion, when the time comes to change personality, use a dice to determine which personality takes over. That way your player has no choice in who they want to step in. A person with this disorder doesn't choose who comes out next.
DM SavageX89
It's a Savage world out there...
In a game I was playing we had a character like this. The player and the DM decided that at the start of every day the player would roll a D20. Under 10 he was the first personality. Over 10 he was the other.
It made the game interesting because they had different skill sets..and it often made for hilarity when he failed a roll..that he would have passed with flying colors if he was of the opposite personality.
I'd recommend against doing it or allowing it.
1) Because actual cases of severe mental disorder are not fun, but terrifying and unsettling.
2) Because actual cases of severe mental disorder are not fun, but terrifying and unsettling.
3) This kind of thing isn't good for a player in the party. Part of being in a "party" is knowing when to let everyone else have spotlight, and this situation becomes the spotlight. I doubt the the other players will really have fun being in the same party as dealing with "randomness" from a party member instead of the environment. It will be funny at first but it will quickly wear thin.
4) Because of the above, if it's to be implemented I see it as a GM's NPC toolbox. Something to run in a horror game, to unsettle the players.
You should also be very careful about balancing this. I just talked a friend through doing a similar thing, and here's what I told him; if you have multiple personalities, each of which is a totally different class that is the same level as the other PCs, then that character will by nature be OP. This is still the case if all you switch is archetype. It doesn't matter that the PC would not be the one to choose when to switch, the fact is that they will have objectively more options potentially available to them at any time.
The concern here is that maybe doing this would feel unfair to the rest of the players, who are limited to one class or multiclass, while this PC seemingly is not limited in that way. I always love the concept, but it's almost impossible to pull off without being either over or under powered, in my opinion.
I know what you're thinking: "In that flurry of blows, did he use all his ki points, or save one?" Well, are ya feeling lucky, punk?
OK so I have a question.
I have a player requesting a multiple personality disorder, but as a result from capture and torture, a demonic soul has been placed in this characters body. Now the question of progression comes up. so if I allow a switch over character,(and I do enjoy the idea very much). Do both personalities level up? are we talking a character that is essentially level 10 but is 2 level 10 characters? or when leveling happens, does the personality in control gain the level? Unless they level up evenly, I do not see a way for the character to be viable, and if they level up at the same time, the character seems to be extremely over powered. for one monitoring the spell slots expended, seems to be a task in general, let alone all of the other issues that may/will arise, (are there different mental scores? monitoring passive perception, saving throws and ability checks, static buffs as one character, (do they dissipate if a change over happens). I really want to make this happen, but don't want to give an unfair advantage.
Any thoughts would be helpful!!
If I were to allow this sort of character, then the mechanical effects of a change would be extremely limited - everything should be focused on role-play differences. Multiple classes, different spells, even different proficiencies are all impossible to balance, and by definition overshadow other players. At most I would have each personality get its own alignment, bond/ideal/flaw, and maybe a language (since the mechanical benefits of that are pretty small). From there it would be up to the player to role-play the differences.
In my campaign, we have a war-forged player character tasked with protecting a special artifact. However, his character has since been uploaded into the artifact (which happens to be a gem akin to the ones in Steven Universe) alongside a flawed AI that prioritizes killing all hostiles.
So, there is now this extremely conflicted character, who's primary directive is to defend it's body (the artifact), and the other half wants nothing more than to put itself in danger no matter how challenging the task at hand.
The switch happens whenever someone says their names (Omega or Epsilon). Interestingly enough, one of our other players (who happens to be an Illithid), chose to take advantage of this-- they said Epsilon's name and told him that a house (with a perfectly innocent family inside) had hostiles in it. He immediately killed everyone inside and the Illithid character ate their brains.
Fun times, fun times! XD
Multiple Personality Disorder a little bit more complicated than that. I mean as in, every personality would have their own ability scores.
Each person can be different in so many things. The brain is extremely powerful. Some personalities are wiser and have more intelligence, especially older personalities, and younger personalities would have lower wisdom. Its the same with any real life ability. In real life, thats how it would be. So if you would like to keep it realistic, having different modifiers makes a lot of sense, keeping it the same wouldn't make sense.
A person with the disorder doesn't choose you're right. The situation does. Normally people with Multiple Personality Disorder got the disorder from being being put into traumatic situations. This person copes by creating personalities that deal with this situation. So when a situation like that, or close to it, arises that personality will come out. So for example, if a person was physically abused at a young age and a personality emerged that help that person fight back, it would make sense that that personality would come out when fighting.
Every case is different, but persoanilties usually are created to deal with certain situations. If a personality that was created for, lets say, relationships, and they randomly came out during fighting that wouldn't make sense. The personality that was created for fighting, or the like, wouldn't even be doing what it was created for.
What if you had a situation where a player creates a Dr. Jekyll & Mr Hyde changeling type character. Using a duel class, they uncontrollable switch between the personality, predominately of Dr. Jekyll, to a Mr. Hyde type personality? For instance, say the player's character was a Bard-Barbarian, who stayed in a fully Bard mindset, with abilities to basically rage. They could be playing music, doing their bard thing, get excited and roll a d20, that forces the player to use a rage, if available as a bonus action, and turn into a barbarian for the attack. As a changeling, the question come in if allowing the player to switch between two different "masks" would be allowed as a reflex-type of action. Is this too OP for the game?
Thanks,
Chances are, yes. Any time you have a character that has access to *more* options than another character, even if it's not fully controlled when they make the switch, it's going to be OP. It will also most likely make the other players annoyed, just because you are effectively playing two full classes while they are stuck with either a single class or multiclass.
That being said, lots of games run homebrew material and intentionally make PCs overpowered in order to have more fun with it. Talk to your DM about the situation. In a "standard" game I'd say don't do it. But DND is rarely standard.
I know what you're thinking: "In that flurry of blows, did he use all his ki points, or save one?" Well, are ya feeling lucky, punk?
All the DM has to do is debuff your experience therefore your levels, because the other personality experienced that situation/conflict. There are plenty of ways of balancing it. Another thing you could do is just not make the split personality have a different class. This fixes a lot of the problems I would see with this build.
I've given this some thought and I wanted to see what others thought about this as well:
Split Persona Feat:
Taking the Split Persona Feat would mean you have two different personalities that should start off conflicting and hopefully learn how to exist with this type of life. There is no cure, it is only learning how to cope and handle. You are only able to take this feat at Lvl 5 and up. This feat also progresses as you level up your main character. Once you take this feat there are levels to how it effects your character. At the beginning, there is no control, its happens in stressful situations and every start of your round in a battle. It is a flip of a coin whether or not you change. With the levels progressing, so does your chances to adapt, and learn to live with this disability. This is NOT an easier way to multi-class, this is a disability that you have to learn how to live with and take control of what it is to you. Depending on your main character, your split or secondary character must be of a different class and different alignment than the original. Example: If your main is a Goliath Barbarian that is Lawful Good, then the secondary character/personality must be at class that is counter to a barbarian, such as a Cleric, Bard, Sorcerer, Warlock, or Wizard. The alignment can still be Lawful but must change to Neutral or Evil . Your secondary could even believe he is a gnome in a Goliath's body.
To prevent any double stacking, each personality has their own stats. So when you first select this feat, work with your DM to determine the secondary character and work out how it effects the main characters story. The secondary personality will have their own base stats and cannot override the mains stats and vice versa. This will prevent rolling a save/check using a different personality stats. The only stat that will cross over is the constitution, the higher of the two shall be used for both characters. Additional or other feats cannot affect this feat. This and 1 other feat may be listed on any additional personalities. Example: A barbarian as a secondary personality must have this feat and have the option to choose 1 other feat on personality upon leveling. No more additional feats may be added there after on personality.
If either main or additional personalities falls unconscious, character reverts back to main.
(Side note: a heart monitor may be worn by player to help determine raise in heart rate to determine stressful situations)
Start of Feat:
Stressful Situation(s) / Start of Every Battle Round
Call either Heads or tails and flip a coin. If you side you called lands up, then the flip is successful and you do not change. If fails, you change into secondary personality.
Some physicality may change based on switch. Example: Goliaths have a CON+1 and STR+2, these stats are lost on switch to Gnome who has a INT+2. The Goliath will shrink in size slightly, but will not become the size of a gnome.
After living with 3 levels of Feat:
Stressful Situation(s) / Start of Every Battle Round
Choose 1 option to continue with:
1. Roll a D20, 11 or higher is successful, anything else is failure. Success deems no change, a failure is a switch.
or
2. Add a third personality to add to your Personality pool. 1D4 is rolled where 1 is the main, 2 is the secondary, 3 is the third personality, and 4 is a reroll.
After living with 5 levels of Feat:
Stressful Situation(s) / Choice
Change is based on previous option chosen:
If option 1 is chosen - anytime a Constitution Check is asked by the DM or requested by the player. With a DC of 10, each success increases DC by 1 and a failure resets to base DC.
If option 2 is chosen - when a Constitution check is asked by the DM, roll w/ advantage a 1D4 to determine personality. If there is a tie, roll until personality is determined (max 6 rolls).
This is just a rough draft of what a split personality feat may look like and I'm always looking for way to improve or develop something like this to play. Thoughts and critiques are most welcomed and appreciated.
I would have him roll percentile to see what personality comes out. It does sound that it's pretty severe though lol they are going to have a blast roleplaying lol.
-Sol