How does initiative work for the giant constrictor snake from the Staff of the Python magic item? [duplicate]

Question

The description of the Staff of the Python magic item reads:

[…] The staff becomes a giant constrictor snake under your control and acts on its own initiative count. […]

As the DM, I’ve been making the player roll initiative when the snake enters combat on the player’s turn. Is this correct?

For instance, if the player’s initiative was 10 and the snake rolls a 20, I have been putting the snake before the player, which means the snake will not attack this round. Is that correct?

The rule makes sense, but applying logic to it doesn’t for me. If the snake rolls high, that should put it ahead in the combat order. It’s fast, but it didn’t go so fast it went back in time, right? It shouldn’t be penalized for having a great initiative roll.

If I were to have the snake go after the player, I’m not sure how I would rank a 20 there.

Answer 1

Yes, if you roll initiative for the snake during the player's turn and you roll high, then they won't act until the next round. However, I do not see this as an issue or anything odd.

Despite the division of turns into rounds, combat acts in a kind of "round robin" with everyone going after someone and before someone else so it doesn't really make any difference after the first round of combat (where it often pays to go first).

Think of it like this: If you entered the room where a D&D game session was taking place and it was part way through combat, and you didn't know the actual initiative scores of the players and monsters, then all you would see would be player A taking their turn, then player B, then monster X, then player C, then player A, then player B, then monster X and so on...

Who actually rolled highest on the initiative and went first? Player A because you just happened to see them go when you walked into the room? Could have been monster X and you just didn't walk in until player A was taking their turn.

So...what I'm saying is: It doesn't matter if the snake gets a high initiative once combat has already started.

Answer 2

Interesting question, I don't think there actually are rules for what to do when someone enters a combat that is already started. The rules even go so far as to say "The initiative order remains the same from round to round." which we know is not always true.

I know that in XGtE there are some summons which say "Roll initiative for the demon, which has its own turns.", but they don't suggest what to do if the demon rolls high. A RAW reading would indicate they simply skip their turn - while a strict RAW reading implies they don't get turns at all! However, there are no explicit rules on what to do, so I think a ruling is in order.

Certainly they need to roll initiative and be inserted into the order, but as you say it makes no sense for them to be penalized for a high roll. I would suggest a reasonable ruling would be have a high rolling snake act immediately.