Are there official guidelines for a DM to change the alignment of a player's character?

Question

Most players in my game chose various forms of Neutral for their character's alignment. However, in time, I notice that two of them are showing very clear signs of actually doing surprisingly good deeds (such as helping strangers, while risking their own life). For one of them in particular, a goliath Blood Hunter, changing from Chaotic Neutral to Chaotic Good could be an interesting change from a perspective of character development, considering his background and actions.

Are there official guidelines for a DM to change the alignment of a player's character? If so, where can I read up on this? I've looked around in the PHB and the DMG, but can't find more information than the sheer basics on the alignment of creatures (and the outer planes). Am I missing something or does Wizards of the Coast (intentionally) leave this up to the DM?

Note: I already have some ideas on how to do this in a subtle manner, but I'd like to understand the Rules As Written before possibly changing them.

Answer 1

There is only one piece of information specifically regarding alignment change in D&D 5e

The Deck of Many Things (DMG, 162) Balance card says

Your mind suffers a wrenching alteration, causing your alignment to change.

This essentially swaps alignment. LE becomes CG, for example. In the Blood Hunter's case, CN would become LN. This card is intended for huge changes in play style that majorly affect the game. Switching from one end of the spectrum to another is a much larger change than switching from neutral to good.

Is it left intentionally up to the DM/players?

On PHB page 122, there is a small section on alignment that says

For many thinking creatures, alignment is a moral choice. Humans, dwarves, elves, and other humanoid races can choose whether to follow the paths of good or evil, law or chaos.

And explains that the good deities who created such races intentionally gave them free will.

An article of Unearthed Arcana from 2015 called Variant Rules also explains that

Alignment is meant to serve only as a quick summary of a character, not a rigid definitions. It's a starting point, but elements such as flaws and bonds paint a much more detailed picture of a character's identity.

From this we can conclude that alignment is not rigid and can be changed, but that this change should be the choice of the PC, not the DM since they have the free will to make that moral choice. That being said, as the DM, you could suggest an alignment change, or advise them that they are playing more CG than CN (once you know their intentions).

What are the affects of an alignment change?

There are very few mechanical effects of an alignment change, but here are all that I can find. I won't give a description of it, but I will provide the page number to see for yourself.

Robe of the Archmagi DMG, 194

Talisman of Pure Good/Ultimate Evil DMG, 207

Sentient Artifacts: In some cases, only characters of the same alignment of the artifact are able to attune with it. DMG, starting 214

Death: When a character dies, they go to the plane of the deity they worship if applicable. If not, they go to the plane that corresponds with their alignment. So Arborea (CG) or Limbo (CN) for the Blood Hunter.

Answer 2

Alignment plays barely any role in DnD 5e rules

Compared to DnD editions before 4e, DnD 5e hardly has alignment as a mechanic - it comes into play in very few, specific places (such as in certain rare monster abilities or sentient magical items). Even spells that seem to reference alignment, like "Protect from Good and Evil" instead protect from certain creature types rather than certain alignments!

Outside the Player's Handbook, there are provisions to change a player character's alignment e.g. if they get afflicted by lycanthropy, but no universal rules basing such changes on player behavior. The GM can of course change a player character's alignment through the GM fiat, but doing so would have hardly any effect without additional house rules regarding alignment.

Overall, if your players are disregarding their alignment, you should talk to the players about whether the players even care about their alignment at all - one of the reasons why alignment's role is so slim in 5e is that an increasing number of players don't. The classic 3×3 matrix can feel simultaneously restrictive and vague, and many prefer to express their characters' motivations and values in more concrete terms such as Ideals, Bonds and Flaws. Your players may also be trying to play according to their alignment without fully understanding what the alignment they chose means in the world you're playing in - expectations regarding particular alignments vary wildly between groups.

If you want to stress alignment's role in your table, that's of course your call, but I would be extra careful about imposing alignment changes on the party - it's likely to be perceived as an antagonistic or arbitrary unless you give them plenty of warnings beforehand. Possibly even then.

Answer 3

It’s up to the DM.

5E still has alignment, but it places much less emphasis on it than previous editions, to the point there are few (if any) mechanics affecting it, partly from the insanity that resulted from nine boxes trying to hold every worldview and motivation ever.

The closest thing it provides in its stead is a set of traits called Bonds, Ideals, and Flaws, which help define a character’s motivations.

There are optional rules in the PHB regarding the new Inspiration mechanic that provide a mechanical basis for the DM to grant bonuses to characters acting within these motivations, as well as sections in both the DMG and Princes of the Apocalypse dealing with the potential for a character to acquire new Flaws in response to certain traumas. These are optional and not terribly comprehensive, but if you’re looking to make motivations reflected in mechanics, they’re good starting points and guidelines.

Citations will come when I have my source books at hand.

Answer 4

As other answers have said, alignment related stuff is mostly left up to the DM and also not that important mechanically. So I am going to focus on your goal, which you mentioned in this comment

It started with the matching of play-style and character sheet, indeed. But I'm mostly interested in stimulating a certain awareness for the players at the table that could then enrich their roleplay and decision making.

If you are looking to make sure the characters are aware of how they are acting, the best way to do that is not saying, it is showing. Going of your example of your blood hunter risking his life to save strangers, an example of how you might show the player that it was a "good" thing to do, could be something like, the next time the players go into some town or village, they run into that previously saved NPC, who has told all of his friends about the good guy that saved him from bandits, and now your good guy PC is very welcome in the village. They let him stay in the inn for free, they are willing to give him information on his quest for free, that sort of thing.

To contrast this with what might result from a neutral character doing the same thing, the neutral character might save that same NPC but ask for money in return. Then, next time they run into each other, that NPC feels like his debt is paid, and they are cordial but nothing more.

To sum it all up, people appreciate characters who do good things, and you don't need alignment to tell them that.

Answer 5

As with so many things, talk to the players. For this one, it might be better to talk to the relevant players individually, in case they have a scheme that they aren't letting the others know about.

For example, if the player of that goliath would feel more comfortable running the character as CG, then there is no question of disagreement, and the character's alignment can simply be changed.

If, on the other hand, he's simply trying to build up a good reputation so that he can abuse it later, that's a thoroughly CN thing to be doing, and no change is necessary.

Answer 6

Even back in 2nd Ed AD&D, when I DM'ed, I told players to think of alignment as a general descriptive element. It is more important to play the character's persona. I didn't force players to choose an alignment, and if a character was role played well, there was no penalty for a character to evolve or change alignment. I am siding with philosophy, and so does 5th Ed D&D.