Certainly! "Law & Order" is renowned for its dynamic cast, which evolved over the show's original two-decade run from 1990 to 2010. Below is a summary of major cast changes that occurred: **Season 1 (1990-1991):** - The series began with a cast that included George Dzundza (Detective Max Greevey), Chris Noth (Detective Mike Logan), Dann Florek (Captain Donald Cragen), Michael Moriarty (Executive Assistant District Attorney Ben Stone), Richard Brooks (Assistant District Attorney Paul Robinette), and Steven Hill (District Attorney Adam Schiff). **Season 2 (1991-1992):** - George Dzundza left the series at the end of the first season. Paul Sorvino stepped in as Detective Phil Cerreta, partnering with Chris Noth's Detective Mike Logan. **Season 3 (1992-1993):** - After Paul Sorvino left the series partway through the third season, Jerry Orbach was introduced as Detective Lennie Briscoe. **Season 4 (1993-1994):** - No major cast changes. **Season 5 (1994-1995):** - Michael Moriarty exited as Ben Stone, and Sam Waterston joined the cast as the new EADA, Jack McCoy. Jill Hennessy also joined as Assistant District Attorney Claire Kincaid. **Season 6 (1995-1996):** - No major cast changes. **Season 7 (1996-1997):** - Dann Florek and Richard Brooks left the series. Carey Lowell replaced Jill Hennessy as ADA Jamie Ross. **Season 8 (1997-1998):** - No major cast changes. **Season 9 (1998-1999):** - No major cast changes. **Season 10 (1999-2000):** - Angie Harmon replaced Carey Lowell as ADA Abbie Carmichael. **Season 11 (2000-2001):** - Chris Noth left the series, and Jesse L. Martin was introduced as Detective Ed Green, partnering with Jerry Orbach's Detective Briscoe. **Season 12 (2001-2002):** - Dianne Wiest joined as Interim District Attorney Nora Lewin, replacing the departing Steven Hill's District Attorney Adam Schiff. **Season 13 (2002-2003):** - Dianne Wiest exited after one season, and Fred Dalton Thompson joined as District Attorney Arthur Branch. **Season 14 (2003-2004):** - Elisabeth Röhm joined as Assistant District Attorney Serena Southerlyn. **Season 15 (2004-2005):** - Elisabeth Röhm left the show at the end of Season 15, and Annie Parisse came in as ADA Alexandra Borgia. **Season 16 (2005-2006):** - Dennis Farina replaced the late Jerry Orbach as Detective Joe Fontana, partnering with Jesse L. Martin's Detective Ed Green. **Season 17 (2006-2007):** - Milena Govich joined as Detective Nina Cassady, replacing Dennis Farina. Alana De La Garza also joined as ADA Connie Rubirosa, replacing Annie Parisse. **Season 18 (2007-2008):** - Jesse L. Martin took a leave and was temporarily replaced by Michael Imperioli as Detective Nick Falco. Jeremy Sisto joined as Detective Cyrus Lupo, replacing Milena Govich. **Season 19 (2008-2009):** - Linus Roache joined as Executive Assistant District Attorney Michael Cutter, working under Sam Waterston's character, who had now been promoted to Interim District Attorney. **Season 20 (2009-2010):** - Anthony Anderson joined as Detective Kevin Bernard, partnering with Jeremy Sisto's Detective Cyrus Lupo. S. Epatha Merkerson (Lt. Anita Van Buren) stayed on from 1993 to the show's end in 2010. This summary highlights the key cast transitions. It's important to note that "Law & Order" had a large rotating cast, and many recurring characters and guest stars appeared throughout the series. Additionally, some actors left and returned in different capacities or as guest stars. Despite its many changes, "Law & Order" managed to maintain its unique format and popularity over its long tenure.