## Can the Chronurgy Wizard’s Chronal Shift ability be used when a creature passes a saving throw with Legendary Resistance?

From Explorer’s Guide to Wildemount, the Chronurgy Wizard’s Chronal Shift ability says:

You can magically exert limited control over the flow of time around a creature. As a reaction, after you or a creature you can see within 30 feet of you makes an attack roll, an ability check, or a saving throw, you can force the creature to reroll. You make this decision after you see whether the roll succeeds or fails. The target must use the result of the second roll.

Using the adult red dragon as an example, Legendary Resistance reads:

If the dragon fails a saving throw, it can choose to succeed instead.

Specifically, here is the scenario:

1. Wizard casts saving throw spell on Red Dragon
2. Red Dragon rolls the saving throw and fails
3. Red Dragon expends one use of legendary resistance to succeed on the saving throw
4. Wizard uses their reaction to use Chronal Shift to force the dragon to reroll the saving throw
5. Red Dragon rerolls the saving throw and fails
6. Red Dragon expends a second use of legendary resistance to succeed the saving throw

In particular, is step 4 of this scenario a valid use of the Chronurgy Wizard’s Chronal Shift ability?

For transparency, this question is a rewrite of this closed question, having this meta post about its closure. In response, I made this meta post that is more generally concerned with re-asking questions that were closed per our dont guess the system policy. Please avoid any meta discussion on this post, instead relegating it to the relevant meta posts.

## Find every path that passes through certain edges

I’m faced with the following problem:

Given

• Directed and unweighted graph, where each edge E has two attributes

Goal

• Find every path through the 3 (or more) given edges

Questions

• Is it NP-hard?
• Is there already an algorithm for this?
• I was thinking about placing a node in every edge and than run Dijkstra algorithm to find the shortest path from A to B and then from B to C. Although, this complicates my graph. Any other ideas? Thanks

## checking whether turing machine passes at least k>2 states before accepting a word

$$L=\{|\exists\,\,w\in L(M)\,\,such\,\,that\,\,M\,\,passes\,\,at\,\,least\,\,k>2\,\,distinct\,\,states\,\,before\,\,accepting\,\,w\}$$

I try to think of reduction to prove that this language is neither RE nor coRE. How to approach this problem? Is there a hint, or intuition?

I usually check whether Rice can be used, but the question here is not about the language itself

## Are there any planes where time passes more quickly?

Are there any planes in 5e where time passes more quickly?

I was just wondering because I was thinking of providing a situation where my players travel to a different plane, and they come back to find that it’s 100 years later. I know I could homebrew it, but I want to know if there is anything official so I don’t “DM BS” my players.

## What happens when exhaustion passes 6th level on an immune creature?

Assume we have a druid/barbarian(beserker subclass).

The druid hasn’t been sleeping for a few nights, and so has 2 levels of exhaustion. There’s a blizzard going on, bestowing another level of exhaustion. He goes into a frenzied rage, taking the exhaustion level to 4. He goes into the Wild Shape of an elemental, gaining immunity the effects of exhaustion. He then sprints enough times to the point where each Dash increases the exhaustion level by 1.

The rules aren’t exactly clear whether exhaustion immunity prevents the exhaustion level from increasing but regardless he won’t suffer the effects of exhaustion.

If he dashes enough to increase the exhaustion level to 6, what happens if he gains another level of exhaustion? Is it possible for exhaustion level to increase past 6. Would this increase the amount of healing/speels/potions that remove exhaustion levels needed to decrease the exhaustion level to a point the Druid could drop Wild Shape without dying?

## If an arrow passes through an illusionary wall of fire created by the Major Image spell, does it reveal it as an illusion?

The Major Image spell description says:

You create the image of an object, a creature, or some other visible phenomenon that is no larger than a 20-foot cube. The image appears at a spot that you can see within range and lasts for the duration. It seems completely real, including sounds, smells, and temperature appropriate to the thing depicted. You can’t create sufficient heat or cold to cause damage, a sound loud enough to deal thunder damage or deafen a creature, or a smell that might sicken a creature (like a troglodyte’s stench).

[…]

Physical interaction with the image reveals it to be an illusion, because things can pass through it. A creature that uses its action to examine the image can determine that it is an illusion with a successful Intelligence (Investigation) check against your spell save DC. If a creature discerns the illusion for what it is, the creature can see through the image, and its other sensory qualities become faint to the creature.

One of my players wants to cast this as a Wall of Fire. He asked me what would happen if an enemy shoots through it.

As noted in the bolded sentence, physical interaction with the image reveals it to be an illusion.

Arrows have no problem with getting through a normal Wall of Fire. Would this reveal the illusion?

## Given n sets of points in the plane find the shortest path which passes from exactly one point from each set

I am trying to find an algorithm for this. You can imagine each set (S1, S2, …, Sn) as points with different colour. Also it isn’t necessarily |S1|=|S2|=…=|Sn|.

For n=1 the problem is simplified into a “Closest Pair” problem, which can be solved with divide and conquer in O(nlogn).

For n=1 we trivially have a single (random) point.

For n=2 we have two sets of points S, Q and we seek to find the (distance of the) closest pair of points p, q such as p in S and q in Q. I have also found an efficient algorithm for this, using voronoi diagrams (https://stackoverflow.com/a/13000634/6625377)

For n>2 things get tricky. I have no clue where should I head to. Let’s say we have x red, y green and z blue points laid down in a Euclidian plane. How do we find the minimum distance of a route passing for one red, one green and one blue point?

Is this some special case of the Traveling Purchaser Problem?

## HTML Form that Passes Information to Hidden Fields Through URL

I am trying to build an html form that is stretched across several pages. My intention is to use the GET method to send all of the fields data in the query string (URL parameters) and then store this data in hidden fields on the next page. I need to know how to append the data to the URL and how to retrieve it on the next page. I think I will need to send information across at least three pages. I have searched for a way to do this but I haven’t really gotten a clear explanation. I am somewhat new to HTML coding. This is the most difficult thing I have attempted to code. Also, (this is not strictly necessary) but I would like to show this information as dynamic text as well. So I can show that certain pieces information have been added to the form. This needs to be separate from the actual form though. Thank you in advance. Any help is greatly appreciated.

## SPF passes when sending email to external recipient, but fails when sending to internal recipient

I have set up an SPF DNS record for our domain. I’ve used our external IP address and that seems to be working fine, when I email to external recipients from my Outlook, SPF passes, since the originating server IP matches.

Now, we also have 8 web servers that send email through the same Exchange 2016 server, however, SPF is failing because the originating sender’s IP is coming up as the internal network IP of the web server (ie, 192.168.1.14, etc.). I can’t imagine having to put our internal subnet in the SPF record.

What am I missing?