## how would i go about giving a context free grammar of a language

I need to give a context free grammar for this language: how would i go about doing this?

{x E {d,f,#}^* | x = u#v with v = v^R for any u,v E {d,f}^*} E = Element

## When did familiars stop giving bonus hit points?

When I first started playing D&D, familiars used to give their Wizard bonus hit points equal to the familiar’s own hp.

For instance, if your familiar had 2 hp, you got a bonus 2 hp. However, if your familiar died or was killed, you lost double its hit points. At the time, Wizards had a d4, so losing your familiar could literally kill you at low levels.

When did familiars stop giving bonus hit points?

## Would giving Artificers cantrip swapping on long rest be unbalanced?

https://dnd.wizards.com/articles/unearthed-arcana/class-feature-variants

Context: I am implementing the Class Features Variant Unearthed Arcana, which does not include Artificer, for a party with several spellcasters and one Artificer.

This UA allows every “known” caster to replace a spell with another of its level on long rest, aka Spell Versatility, and every “prepared” caster (with cantrips) to replace one of their cantrips with another on level up, aka Cantrip Versatility.

However, the effect of Cantrip Versatility is already inherent to the Artificer class. I’ve consider allowing the Artificer to have Spell Versatility for cantrips. But I’m not certain if this is balanced or not since it goes beyond what other “prepared” casters received.

I’m open to suggestions for alternative replacements/enhancements that make implementing this UA more fair for the excluded class.

## Is giving my character amnesia about it’s backstory a bad idea?

During my first campaign as a player I had a issue with my DM regarding the background I gave to my character. It was my first time creating a background for my character and I loved doing it, so much that my backstory became quite big. (I gave my DM a short summary to make his life easier).

While I loved creating a backstory, I wasn’t too comfortable with going all in with roleplaying. For this reason I added a piece in my backstory where my character was cursed, couldn’t remember where he was from and he was now wandering around looking for answers. I just wasn’t ready to dive straight into roleplaying this backstory and wanted to learn RP step by step.

A couple sessions after I handed over my backstory, my DM briefly mentioned his dislike towards my backstory. He did this in a single comment, away from all the other players which went along the line of “Who gives their player amensia, what kind of person does that?” At that time I didn’t know how to respond and not too long after that we stopped playing anyway, but the comment still makes me wonder if it really is a bad thing to do?

## Error while giving initial condition in NDSolve

I am trying to solve following differential equation $$\frac{d^2y}{dx^2}+(a+b \frac{2}{\pi}\tan^{-1} x)y=0$$ with the initial condition $$y(-10)=e^{10i\sqrt{a+b}}$$ and $$y'(-10)=-i\sqrt{a+b}e^{10i\sqrt{a+b}}$$.

To implement it I write the following code

s = ParametricNDSolve[{y''[x] + (a + b (2 + 2/Pi ArcTan[x])) y[x] ==  0, y[-10] = Exp[I 10 Sqrt[a + b]], y'[-10] = -I Sqrt[ a + b]*Exp[ I 10 Sqrt[a + b]] }, y, {x, -10, 10}, {a, b}] 

But I am getting an error that ParamatericNDSolve expects equation or list of equations instead of $$e^{10i\sqrt{a+b}}$$ in the first argument. Can anyone point me out where am I making the mistake?

## How do I balance giving Simic Hybrid extra Animal Adaptions

It’s my turn to DM, and the previous DM want to play a Simic Hybrid, but they want to use three of the animal adoptions available, instead of two.

I want to give them this, but I don’t know how to counter this with something that would make it balanced. How do I balance this?

## Giving my players a dragon [on hold]

I’m starting a new campaign and I was thinking of giving my players a newly hatched baby dragon in the start of the campaign. I think it would be cool if when it’s grown a bit that they can have it as a mount/ “pet” but it’ll probably be a bit overpowered. What are your thoughts on the idea and do you have any suggestions on how I could maybe nerf the dragon not to make it super over powered to have a dragon as a pet ( they would be around 4th level when they get the dragon and it wouldn’t be grown enough to ride or use in combat until maybe 8-10th level ).

edit- The setting for the campaign is a world i’ve created hence why if I go with giving them a dragon i’ll homebrew it so that dragons mature a lot quicker and I’ll just motivate it with some of the other weird stuff that happens in the world. So yeah I’m aware that it would otherwise take a few hundred years to mature

## Is there anything in the rules giving Loxodons disadvantage on Stealth checks?

I’m curious if there is a ruling on this topic. Specifically the debate was over whether a Loxodon Way of the Shadow Monk could benefit from the massive stealth advantages and ninja-teleportation. This would apply equally I presume for Centaurs and other larger (but still medium) playable races.

Speaking of “flavor” it seems a Loxodon/Centaur ninja would be highly ineffective. A 7ft tall 400lb elephant probably wouldn’t make a great ninja, right? It makes sense from a world concept level.

But is there actually anything in the rules that would give these large (but still Medium-sized) creatures disadvantage on Stealth checks?

## Nmap giving different result between Mac OS scan and Linux (Kali) scan

I try to do a simple TCP scan on an Kubunt VM (is on VirtualBox), from two different OS. From the Host (Mac OS system) and from a Kali Linux VM (tried VirtualBox and Parallels also). Kali Linux (same result VirtualBox and Parallels) gives:

From Mac OS (run with root privileges, to simulate the same scan from Kali):

So run a Nmap scan from Mac OS gives more open ports on the same VM, with the same privilege of scan, etc. Mind blowing…

If I scan just a port (from Kali VM) try the 110, the result is that is closed:

Why is it happening?