Shulchan Arukh, Orach Chayim 690/שולחן ערוך·אורח חיים תר״צ

1Laws of reading megilahOne should read the Megillah either standing or sitting; but in shul in the first place he shouldn't read it sitting because of honor for the Congregation. Rema: it is forbidden for a Chazan to read the Megillah until they said to him "read". [Mordechai, Perek HaKoreh]

2Even only two, or even ten people, can read (the Megillah) together and they can fulfill the obligation and the obligation of the people listening to them.

3You need to read the Megillah entirely and from a scroll; and if you read it by heart you do not fulfill your obligation. You need to have the whole scroll in front of you in the first place, but if the Sofer left out in the middle some letters even until half of it (the Megillah) and you read it, then the one who read it by heart fulfills his obligation. Rema: even if (the Sofer) left out letters from the beginning or the end, even if he left out just a little, one does not fulfill one's obligation (if you read from it by heart) [the R"an]. And even in the middle, specifically, where an entire topic is not left out [Beis Yosef]. However, if more than half (was left out), (or) even if the letters were written but they were unclear/blurry and their writing was not recognizable, it is pasul.

4One who holds in his hand a Megillah that is not kosher may not read it with the Chazan (or reader in this case); rather he should listen and be quiet. Rema: Similarly, no one should assist the Chazan by mouth. And therefore regarding those verses that the congregation reads, the Chazan must go back and read them from a kosher Megillah [Beis Yosef in the name of Shibulei Leket]

5If one reads it in a grating manner, in other words, one stops and tarries and then afterwards goes back to the place that he stopped - even if one tarried in order to finish it all - he has fulfilled his obligation. Rema: And even if one speaks in the midst of it. But, we rebuke one who speaks in the midst of it, as like [the law is] below Siman 692, Seif 2 [the Rashba].

6One who reads the Megillah incorrectly has not fulfilled his obligation. If one reads one verse and then skips over the second verse and read the third verse, and then afterwards he goes back and reads the second verse, he does not fulfill his obligation because he is reading one verse incorrectly. Rather, what does he do? He begins from the second verse that he forgot and continues to read in order.

7One who reads the Megillah by heart does not fulfill his obligation.

8One who speaks a different language (other than Hebrew) who hears the Megillah which was written in the Holy Language (Hebrew) fulfills his obligation even if he does not know what they are saying.

9If there is a writing of a translation, or [the Megillah] is written in another of the languages of the Non-Jews, one does not fulfill his obligation by reading it [in that language] unless he is familiar with the language itself. However, if [the Megillah] was written in Hebrew and one reads it in Aramaic, one does not fulfill his obligation, because this is like reading it by heart. Just like the reader does not fulfill his obligation in this manner, so to one who hears it from him. RAMA: However we are not concerned about which language it was written in. [Beis Yosef]

10One who knows a foreign language, and knows the Assyrian language, he does not fulfill his obligation with that language. And there are those who say one does [fulfill one's obligation]. Rema: And if the writing is in two languages, he who understands it fulfills his obligation. [Beis Yosef]

11One should protest against those reading the Megillah to women in a foreign language, even though it is written in a foreign language.

12If one is reading and dozes off, given that he didn't completely fall asleep, he has fulfilled his obligation. However if he heard it [from someone else] while dozing off he has not fulfilled his obligation.

13If a writer reads a verse in the Megillah in order to copy it and he writes it, if he intends in his heart to fulfill his obligation [in this manner] he does fulfill. This is where he writes the whole thing before him in the Megillah that he is copying from. And likewise if he is proofreader and also if he is an expositor who reads a verse in a whole Megillah and expounds upon it; if [these people] intend in their heart fulfill their obligation [in this manner] they do fulfill. And he must not delve into other matters while he expounds upon the Megillah as this is forbidden.

14One who reads the Megillah must intend to fulfill the obligations of those who hear it from him, and the one who hears must intend to fulfill his obligation through hearing it. And if the reader is the chazan he likely intends to fulfill the obligation of all who hear from him, even those in the back of the shul. We are not precise in correcting reading errors. And there are those who say [that we are not so precise] specifically with errors which don't change the meaning such as the two students that were sitting with Rav, and where one read it as Yehudim and another reads it as Yehudiim, and neither were corrected. But [according to this second opinion] regarding other errors [which do change the meaning] he does not fulfill their obligation [if he is not precise in the language].

15One must say the names of the ten sons of Haman in one breath, so that we may know that all of them were killed and hung as one. RAMA: And specifically initially. However, after the fact, if one paused between them he has fulfilled his obligation. [Tosefos; Avudraham; Mahar"il] Initially, it is our custom to say everything in one breath from "500 men, and Parshandata, et" until the word "aseret". [Mahar"il in the name of the Rokeach]

16One must say "cursed is Haman", "Blessed is Mordechai", "cursed is Zeresh", "Blessed is Esther", "cursed are all those who worship idols", "Blessed are all Israel". And one must say "and Charvonah, may he be remembered for good".

17It is a custom of all Jews that the reader reads and spreads out [the Megillah] like a letter in order to make the miracle seen. And when one finishes, one goes back and wraps it all up and makes a blessing. Rema: There is what is written that we say four verses of redemption in a loud voice, [the verses are] "A Jewish Man", "And Mordechai went out", "The Jews had light", "Because Mordechai the Jew" and such is the custom in our lands. [Hagahos Maimoni; Kol Bo; Avudraham]. And then the reader goes back and reads these verses. It is also written that the young children are accustomed to draw pictures of Haman on trees or stones or to write the name of Haman on themselves and to strike one against the other in order to blot out his name according to "The name of Amalek shall surely be erased" (Devarim 25:19) and "But the fame of the wicked rots". (Proverbs 10:7). From this is derived the custom that we strike Haman wen we read the Megillah in the synagogue [Avudraham]. We must not nullify any custom nor should we ridicule [any custom] because "לא לחנם הוקבע". [Beis Yosef]

18The Megillah [of Esther is read] on the 14th [of Adar in unwalled cities] and on the 15th [of Adar in waled cities], [and] one must make sure that [he is attending the Megillah reading among] a [congregation of at least] ten men. And if one cannot find [a congregation of] ten men, one may read it by himself. Rema: It is uncertain if women are [legally counted as composing part of] a congregation of [at least] ten men [Hagahos Ashiri; Tur]. If [the Megillah] is read in a congregation [of at least ten men], and an individual happened to not hear the reading, he should read it on his own (even though ideally, one must seek a congregation of at least ten men), since [at least] it is being read in his city amongst a congregation [of at least ten men] [Beis Yosef in the name of Orach Chayim]. And when an individual (not amongst a community) reads it during the time [period when it is legally required], he must make a blessing (special blessing acknowledging the requirement of reading the Megillah) on it. [Beis Yosef]