The rules for copying spells from other spellbooks are rather clear: you need time and money. However, in case you acquire a new spellbook, things are more fogged.  Can a wizard use two spellbooks at the same time? If so, you only need time to understand it and can forego the costs, right? Otherwise, what happens if you lose your spellbook? Or, must you use just ONE spellbook, possibly attuning to it?
Whether the players killed a mage and got his spellbook(s) or they met with a nice wizard who let him or her learn a spell from his spellbook, can a player prepare a spell from a spellbook that isn't his or hers?  I'm asking because the PHB p. 114 says:     [...] Preparing a new list of wizard spells requires time spent studying your spellbook and memorizing the incantations and gestures you must make to cast the spell: at least 1 minute per spell level for each spell on your list.    emphasis mine   Further, the block on the left as a Copying a Spell into the Book ("the" Book as in "your" Book, since it appears in the block titled Your Spellbook), which explains how you can copy a spell from one book to another, assuming the book is from a stranger, it cost more and takes more time. It actually says:     [...] deciphering the unique system of notation used by the system of notation of the wizard who wrote it. [...]   It continues saying that you have to learn the various parts of the spell (verbose, material, gesture.)  This makes it sounds like a wizard would have a really hard time to prepare a spell from another's spellbook. Is that the case?
How to create a site in a sitecollection on a remote SPServer using C# What are some good examples of a function  $f : \mathbb{R} \to \mathbb{R}$ where its derivative is equal to its inverse? I attempted to find a monomial that satisfied it by starting with $f(x) = ax^b$ and showing that $f^{-1}(x) = f'(x) \implies b-1=\frac{1}{b} \implies b=\phi$ and got $$f(x) = \frac{x^\phi}{\sqrt[\phi]{\phi}}$$ Which seems to work according to WolframAlpha, but I'm having trouble double-checking it. Any other ideas? How do I skip specific tests when building an rpm? I am building an RPM of git version 2.13.0. The build has gone ok but one of the tests are failing:  Config variable ${LIB_HTTPD_SVN} is not defined Config variable ${LIB_HTTPD_SVN_PATH} is not defined   I cannot find any info about these variables so I was going to just skip the tests. How can I do that? MySQL: LEFT JOIN not working as expected I have recently upgraded SQL Server 2000 database to 2008 R2.    What I did was:   Shutdown SQL Server 2000 (express) service on old machine, Move datafiles (mydatabase.mdf and mydatabase.ldf) to new machine, Run SQL Server Management Studio 2008, Connect to local database engine, Attach datafiles to database. Change the compatibility level of database to SQL 2008 (100).     Question: What else should I do to make migration complete?  I want to:   use new features like checksumming and full recovery model, make this database to be exactly as it was created in SQL 2008 R2, make this database to be fully compatibile, correct and be perfect suited for new, SQL 2008 R2 database engine.     In other words: I just want to know how to correctly and completly convert old SQL 2000 database to new 2008 R2 database, be calm that everything is done right and be happy with all new features.    I'm asking this question, because I've found a lot of sites on the Internet that says so many different things that makes me confused: some say that it is required to rebuild indexes, another says to do other things... and now I know nothing so I want to hear experienced person opinion and clear, step-by-step instructions. I work for very small company, I'm on my own and I don't want to screw things up.    Sir, I'm really impressed with your answer, I wasn't expecting so much.    So some comments:   The database is now in production. As I said, it was upgraded using deattach-attach method as I desribed in first post and as described on MSDN:  It had to be done quickly, so I was forced to do it that way. Let's forget about how inappropriate could it was and focus on current situation. The users/persmission is not a problem here - there are only few and permissions are simple. The application which use database is compatibile with SQL 2000 till 2012 so this is not a problem either. The database file (MDF) isn't big - only about 1GB.     Few more questions:   You recommend to use backup/restore method, but I did as written above, so can I encounter any problems now? Everything worked without any problem. About checksumming and full recovery model: it wasn't available/enabled on SQL 2000, so I want to use them now. You said that the only thing I need to do is to enable those options in database properties? I've read somewhere, that it isn't enough and I should also rebuild indexes or something. I really don't know, I just asking. I'm prepairing to migrate this database to SQL 2012 - so first it was from SQL 2000 to 2008 R2, now it will be from 2008 R2 to 2012 (it was impossible to do this directly because of lack of support of SQL 2000 databases in SQL 2012). So I understand that I should follow your guide: backup it in 2008 R2 and restore in 2012, then do the rest of your tips, right? Please explain me the backup/restore method: Is it like a dump of database to SQL queries and then restoring it by executing a bunch of queries? Will this method by the way "defragment" my database? If not, how to defragment/optimize it manually? As we were using SQL 2000 Express for years (no management interface), we were doing backups simply by stopping engine and RAR the DATA directory. For now, as we are on SQL 2008, isn't this still better than using backup function in Management Studio? Full recovery mode with frequent Transaction log backups - Where is the Transaction log stored - is it the LDF file? How sould I backup it properly?     I know that my questions may sound silly, I'm not professional database admin, but I am the only person here who can do such "hard core" task like upgrading the database engine. I'm also sure that your knowleadge will help a lot to other people like me.  Thank you very much for your time and knowleadge, I really appreciate this. Definition of Statistic I keep seeing conflicting definitions of a statistic. Is a statistic a random variable such that it is a function of the random variables of a random sample? Or is it the value of the function of the random sample, after each random variable of the random sample has taken on a specific value?   $$(1) \ S=f(X_1,X_2...X_n)$$  $$(2) \ s=f(x_1,x_2...x_n)$$  I haven't been able to get any clarification for this and I've seen the term statistic describe both situations Are there any rules on when to use icons vs. icons with text vs. just text links in a web application?  For example:    vs.   save  vs.  save    Extra question: Is  save -or- save  preferable? How to tell what method was used to log in (Password vs. Keyfile) from the bashrc Is there a way how you can check what auth method the user which just logged in to an account were using?  I like to print out a warning after login if someone is using a password instead of a keyfile.  Sure one solution is to check the ssh-logs. But is there a nicer way to do this? Since looking up logs could impact performance depending on the log size and method you use to gather this information.  We are using SUSE and Ubuntu. Quick question: what is the compiler flag to allow g++ to spawn multiple instances of itself in order to compile large projects quicker (for example 4 source files at a time for a multi-core CPU)? Why I can't scan the WhatsApp QR? Cycles Normal Bake does'nt bake indents that are not tapered Incubated but not hatched egg I got the message "oh" and it showed my egg. Before I could do anything the server went down. When I got back on my egg was gone. Is there anything I can do to retrieve my incubated but not hatched egg? How can you profile a Python script? and other coding contests often have a maximum time to run or people boast of how fast their particular solution runs. With Python, sometimes the approaches are somewhat kludgey - i.e., adding timing code to __main__.  What is a good way to profile how long a Python program takes to run? Cardioid in coffee mug? Derivation of the general forms of partial fractions I used the upgrade manager to upgrade from 17.04 to 17.10. When I start the machine, I only get a black flickering screen now. I was using the nvidia binary drivers before the upgrade.     NOTE: This question (and answer) relate to a specific issue when upgrading from 17.04 to 17.10 while using Nvidia or AMD binary drivers. You might experience a completely different issue. For that please see the more general question . I'm trying to figure out a good workflow for developing scripts and add-ons in Blender. Here's what I'm currently doing as I try my luck with a PyNode add-on:   Open blender Create a text editor panel Open my script (external text file) Edit my script in a nice external editor Reload the script Save the .blend file Run the script   Now that I can see what my code does, this Blender instance has been modified, so I can't (make changes to my script and) run my script again. So I do this:   Close blender Open blender with the .blend from step 6 and repeat steps 4-7, over and over and over..   Is there a better workflow for this sort of thing? Given that $xyz=1$, prove that $\frac{x}{1+x^4}+\frac{y}{1+y^4}+\frac{z}{1+z^4}\le \frac{3}{2}$ Given that $xyz=1$, prove that $$\frac{x}{1+x^4}+\frac{y}{1+y^4}+\frac{z}{1+z^4}\le\frac{3}{2}.$$  I proved this with , but: is there a better/more elegant way? Mods folder missing from .minecraft folder I have Windows 10 and when I go to look in my .minecraft folder in the AppData folder, the mods folder is not there.    How can I find the mods folder? Using principal component analysis (PCA) for feature selection