## Changing sign of elements of a list on even positions

I have a list of lists of equal sizes (odd or even), e.g.

``list={{1,-2,3,1,3,4},{3,5,6,-1,9,0},{1,-2,-4,-5,1,5},{1,-1,2,3,5,4},...} ``

I would like to change signs of every element which is on even or odd position. In the example above, for the choice of change on even positions, it should give the following result:

`` listnew={{1,2,3,-1,3,-4},{3,-5,6,1,9,0},{1,2,-4,5,1,-5},{1,1,2,-3,5,-4},...} ``

What is the most effective way to achieve this? (The length of `list` may be huge here).

## Enemy Follows the Player Even His Death Animation Triggered

I have a 2D game project and I am coding but still on learning level. If I put simply, its based on player’s escape and enemy follows to hurt him. Important case is, I am using A* PathFinding for this because there are obstacles for enemies and they need to pass them.(A stars pathfinding here: https://arongranberg.com/astar/ )

Problem is: Enemy following Player, wherever he goes on the flat rectangular scene, but when I kill enemy while following, his death animation triggered and he dies in 3 seconds but he still keeps following me while he is dying process going on and even when he is lying down on the ground. Simply flies to me.

What I need is to make him stop at that very location when his "isDead" parameter gets triggered. Because of A* using, I couldn’t find a way to do it and override A* somehow.

This is the code I use for attack when close to player, and isDead function:

``public float stopDistance; private float attackTime; private bool isCloseForAttack; public float attackSpeed;  public void Update() {     animator = gameObject.GetComponent<Animator>();      if (player != null && !isDead)     {         if (Vector2.Distance(transform.position, player.position) > stopDistance)         {             animator.SetTrigger("isNotRunning");         }         else         {             animator.SetTrigger("isRunning");             if (Time.time >= attackTime)             {                 StartCoroutine(Attack());                 attackTime = Time.time + timeBetweenAttacks;             }         }     }      IEnumerator Attack()     {         player.GetComponent<Player>().TakeDamage(damage);          Vector2 originalPosition = transform.position;         Vector2 targetPosition = player.position;          float percent = 0;         while (percent <= 1)               percent += Time.deltaTime * attackSpeed;         float formula = (-Mathf.Pow(percent, 2) + percent) * 4;         transform.position = Vector2.Lerp(originalPosition, targetPosition, formula);         animator.SetTrigger("attackMove");          yield return null;      } } } ``

## Looking for (even unofficial) duelist variants

As @KRyan told me, it seems like the duelist PrC is a little bit broken. But my party is currently lost in the middle of savages countries far from any civilization and it is very unlikely that I meet any PrC coach before a long time.

I am currently swashbuckler 5/Dragonmark heir 2/duelist 2/blade of orien 1, and I was planning to keep leveling as a duelist for some time. I think this build is not completely unbalanced compared to the builds of my teammates as they don’t put out as much optimization effort as I do. I chose to train the class knowing its flaws, but I considered it was a realistic evolution for a swashbuckler.

Nevertheless, some duelist levels like the 4th: “+2 on reflex saving throws” are really boring, so I am beginning to research additional content about this PrC like official alternative levels or widely acknowledged homebrews.

EDIT: I am specifically looking for optimizations of the duelist class, which from my point of view essentially sums up to “a character with style (like the swashbuckler) using a rapier and no armor and adding INT to AC“. What I am expecting is mostly alternative class levels, either as a few errata or a total redesign. I would rather it being some already well known content so that it would be easier to negotiate it with my DM.

(In case you were wondering, I did try negotiating taking only 3 levels of swashbuckler, but our DM insisted on us taking 5 level on our baseclass before multiclassing. Plus I liked the flamboyance of this type of character and did not want to change it to much. KRyan suggested me rebuilding as Factotum or Warblade but they are from books that are not allowed in my campaign.)

## what is great fortitude or even fortitude specifically in rpg games, playing low magic age which has this

I find fortitude confusing, do not know whether or not it is good, bad whatever. I did look up what fortitude is and the explanation is more than confusing. I did also look up What happens if Fortitude sinks to 0? as well as https://rpg.stackexchange.com/search?q=fortitude . The game itself seems to be dnd-inspired, at least according to the developers and the people who are talking about it. Low Magic home page.

According to some it is more preferable that I talk or ask about fortitude in D&D. I haven’t ever played a paper-and-pen rpg so don’t really know.

From what I gathered from other people is that the game uses D&D 3.5e and uses ‘evolved OGL rules’ made by wizards of coast.

## FullSimplify a expression with a even function“`Df[x] == Df[-x]“`?

I want to simplify a expression with a even function`Df[x] == Df[-x]` like:

`FullSimplify[-(1/2) Df[x - x4] J[x] - 1/2 Df[-x + x4] J[x], Assumptions -> {Df[x] == Df[-x]}]`

This code can not give the desired result like `-Df[-x + x4] J[x]`.

And the strange thing here is that if I replace x4 with x2, it works well.

`FullSimplify[-(1/2) Df[x - x2] J[x] - 1/2 Df[-x + x2] J[x], Assumptions -> {Df[x] == Df[-x]}]` will give `-Df[-x + x2] J[x]`.

So any solutions here for x4 or arbitrary symbol?

## Why if the targetToFollow(Player) is rotating and facing the transform the player can get close to the transform even touch it?

``using System; using System.Collections; using System.Collections.Generic; using System.Linq; using UnityEngine; using UnityEngine.UI; using UnityStandardAssets.Characters.ThirdPerson;  public class Follow : MonoBehaviour {     public Transform targetToFollow;     public Transform missionTarget;     public GameObject naviParent;     public ThirdPersonCharacter thirdPersonCharacter;     public Text textDistance;     public Text textSpeed;     public float lookAtRotationSpeed;     public float moveSpeed;     public float followRadius = 1.5f;     public float fastRadius = 5f;     public float speedBoost = 0.5f;     public bool follow = false;     public bool reachTarget = false;      private bool isNaviChild = false;     private Vector3 lTargetDir;     private float originSpeed;     private float originFollowRadius;      void Start()     {         originSpeed = moveSpeed;         originFollowRadius = followRadius;          if (reachTarget)         {             moveSpeed = thirdPersonCharacter.m_MoveSpeedMultiplier * 5;             followRadius = 0.1f;         }     }      // Update is called once per frame     void FixedUpdate()     {         if (follow)         {             if(reachTarget)             {                 moveSpeed = thirdPersonCharacter.m_MoveSpeedMultiplier * 5;                 followRadius = 0.1f;             }             else             {                 moveSpeed = originSpeed;                 followRadius = originFollowRadius;             }              lTargetDir = targetToFollow.position - transform.position;             lTargetDir.y = 0.0f;              Turn();              float ms = moveSpeed;             var distance = Vector3.Distance(transform.position, targetToFollow.position);             // Compute a position no further than followRadius away from our target.             Vector3 fromTarget = Vector3.ClampMagnitude(                 -lTargetDir, followRadius);             Vector3 stopPoint = targetToFollow.position + fromTarget;              // Compute a speed that's faster when far away and slower when close.             float speedBlend = Mathf.Clamp01((distance - followRadius) / (fastRadius - followRadius));              ms = moveSpeed + speedBlend * speedBoost;              // Move as far as we can at our speed ms to reach the stopPoint, without overshooting.             transform.position = Vector3.MoveTowards(transform.position,                 stopPoint, Time.deltaTime * ms);              var dist = Vector3.Distance(transform.position, targetToFollow.position);             if (dist < 0.1f && isNaviChild == false && reachTarget)             {                 transform.parent = targetToFollow;                 transform.localPosition = new Vector3(0, 0, 0);                 transform.localRotation = Quaternion.identity;                 transform.localScale = new Vector3(0.001f, 0.001f, 0.001f);                  isNaviChild = true;             }         }     }      private void Turn()     {         transform.rotation = Quaternion.RotateTowards(transform.rotation,                 Quaternion.LookRotation(lTargetDir), Time.time * lookAtRotationSpeed);     }      private void Mission()     {      } } ``

When the bool flag follow is true and the bool flag reachTarget is false the transform that this script is attached to is moving towards the targetToFollow and then when the targetTofollow(in this case the target is the player that move by the kleys WSAD) move the transform is following him with keeping distance to follow that’s the followRadius.

The problem is that if I rotate my place to face the transform and then moving the player forward he will be able to get too close to the transform even touching it.

But in my logic if the radius to follow is 1.5 so even if the player will face the transform and try to move forward to it the transform should always move to the back of the player or move back and keep the follow radius of 1.5 or if the follow radius is 66.3 then 66.3

The player should not be able to get so close to the transform.

How can I solve it ?

Pact of the Blade says "You can’t affect an artifact or sentient weapon in this way" in regards to making a magic weapon your pact weapon.

A Hexblade is a sentient magic weapon, as read in XGtE, "a force that manifests in sentient magic weapons…"

It sounds to me like you cannot turn your patron into your pact weapon, which would be very self defeating because you’re effectively making a contract with a living weapon to be able to better wield other weapons.

Am I interpreting this correctly or overthinking it?

## Must a Ranger’s spellcasting focus be druidic, or can it be arcane (or even holy)?

This question was inspired by the question about what constitutes a bardic spellcasting focus. It has been somewhat overcome by Tasha’s Cauldron of Everything (p. 57) which explicitly describes a Ranger’s Spell focus as a druidic focus, but since not all tables will use that optional rule the question will remain up.

A Ranger’s spellcasting ability is described thusly:

By the time you reach 2nd level, you have learned to use the magical essence of nature to cast spells, much as a druid does.

As discussed here, a Ranger meets the definition of a spellcaster in that a class feature, not an item, grants the character the ability to cast spells. While that would support a Ranger using a spellcasting focus, only three spellcasting foci get explicit treatment in the rules (unless I missed a spot).

• A Holy Symbol (Basic Rules p. 48.)
• A Druidic Focus (Basic Rules p. 48.)
• An Arcane Focus (Basic Rules p. 47.)

Aside: I may be making a leap. The text on druidic focus does not mention Rangers. The leap is based on the Ranger class spellcasting feature being explicitly tied to druidic spellcasting in the brief text covering that class feature.

• Spellcasting Focus:

You can use a druidic focus (see “Equipment as a spellcasting focus for your druid spells).

• Druidic Focus.

A druidic focus might be a sprig of mistletoe or holly, a wand or scepter made of yew or another special wood, a staff drawn whole out of a living tree, or a totem object incorporating feathers, fur, bones, and teeth from sacred animals. A druid can use such an object as a spellcasting focus.

In a case of specific over general, Paladins and Clerics are called out as being able to use a holy symbol as a spellcasting focus (Rangers were left out). This left me with two questions, only one of which is germane to the Ranger2. The Ranger gets no specific call out (unlike the Paladin) on whether the character can use for a spellcasting focus a holy symbol, a druidic focus, or an arcane focus. (Since the Ranger is a spellcaster, there’s got to be something that the class can use to substitute for material components, right?)

### Why would this matter?

A lot of Ranger spells have material components. Just reviewing the SRD (which isn’t the whole list) the following spells calling out "V,S,M" in the components line:
Level 1
Alarm, Animal Friendship, Detect poison and disease, Goodberry, Jump, Longstrider
Level 2
Animal Messenger, Barkskin, Darkvision, Locate Animals or Plants, Locate Object, Pass without a trace, Spike Growth
Level 3
Nondetection, Water Breathing, Water Walk, Wind Wall
Level 4
Conjure Woodland Beings, Freedom of Movement, Locate Creature, Stoneskin
Level 5
Commune with Nature

### The adventuring Ranger won’t always be in a "home" environment

Considering that terrain types generally coincide with Druid Circles …

Arctic, Coast, Desert, Forest, Grassland, Mountain, Swamp (I’d call seaborne adventure close enough to Coast for these purposes)

… it might be impossible to find mistletoe in the desert when a material component is needed.

### Question restated

Can the Ranger use an arcane focus or a holy symbol as a spellcasting focus, or is the ranger constrained to the druidic focus (a holly symbol1?) based on the class’ spell casting feature being heavily druidic in nature1?

1 Please excuse the puns. Sometimes we can’t help ourselves.
2 I leave the idea of druids being priest of nature (mostly gotten around with Nature Domain clerics) for another question regarding a holy symbol as a spellcasting focus for a druid.

## Can switching from .com TLD to non .com TLD affect emails even if MX records migrated correctly

I have a high-level question about a customer that switched from a .com TLD to a .fun TLD. They didn’t switch hosting, only their TLD. They’re now having issues with their emails, personal and campaign based, being blocked.

Before I dig in to the technical stuff, I wanted to know if anyone had a similar issue. Before I dig in to MX records and such, I didn’t know if there were known TLD issues with ones like .fun, etc. Sorry if this is a vague question. And I promise I’ve been googling and asking first!