By Ryan Pike for WrestlingObserver.com

WWE has gotten really into SummerSlam this year, moving the event from Los Angeles to Brooklyn and pumping it up to four hours (and ten matches). To help you navigate all the chaos of the big event, here’s a Casual Fan’s Guide to SummerSlam 2015.

BROCK LESNAR vs. THE UNDERTAKER

-What: A singles grudge match.

-Who: Brock Lesnar is a beast of a man; a former WWE, NCAA and UFC Champion, he’s arguably the most terrifying person in WWE history and their most accomplished legitimate athlete. He’s a good guy now because the crowd admires his ruthless efficiency. The Undertaker is basically a zombie; he debuted in 1991 and has both incredible fighting prowess and vaguely-defined magical powers. This is Undertaker’s first SummerSlam appearance since 2008 and his 16th overall – more than anyone else in WWE history.

-Why: Lesnar famously ended the Undertaker’s WrestleMania undefeated streak at WrestleMania 30. The Undertaker was upset about it, and got out-and-out mad about it when Lesnar kept bringing it up in promos. Undertaker cost Lesnar the WWE Championship at Battleground – a year and a half after WrestleMania 30 – giving Lesnar an incentive to take out Undertaker once and for all.

-Fun Fact: This is the tenth time in SummerSlam history that the main event is not a title bout of some kind. Undertaker has been in two of them – in 1994 against the Fake Undertaker and in 2008 against Edge in Hell in a Cell – while Lesnar faced Triple H in a non-title main event in 2012.

WWE Champion SETH ROLLINS vs. WWE U.S. Champion JOHN CENA

-What: A singles bout for both the WWE World Heavyweight Championship and the WWE United States Championship.

-Who: Seth Rollins is the reigning WWE World Heavyweight Champion, having won it at WrestleMania when he cashed in Money in the Bank during the main event. He’s kind of a jerk, and has retained the title by hook or crook for the past several months. John Cena is a 15-time World Champion (12 WWE reigns, 3 World reigns) and the current United States Champion, having won that title at WrestleMania as well. Cena’s been the textbook definition of a fighting champion, basically the opposite of Rollins, having a running Open Challenge on most editions of RAW since he won the title.

-Why: Rollins is the poster-child for The Authority, a heel group led by Triple H and his wife Stephanie that claim to be about what’s best for business. They formed initially to keep Daniel Bryan away from the WWE Title in 2013 and they’ve also targeted guys like Roman Reigns and Cena as guys they don’t think are worthy of being WWE standard-bearer. Cena doesn’t like that Rollins is being protected and never defends his title in fair fights. Rollins doesn’t like Cena, an elder statesman of the WWE, being around and taking chances away from younger guys.

-Fun Fact: The WWE Title has been defended 24 times in SummerSlam history. The champion has left the event with the title 17 times. However, it’s changed hands three times in the past two SummerSlams; Daniel Bryan beat John Cena in 2013 but immediately lost the title when Randy Orton cashed in Money in the Bank, while Brock Lesnar beat Cena for the title last year.

RANDY ORTON vs. SHEAMUS

-What: A singles grudge match.

-Who: Both men are tough guys and former WWE Champions. Orton’s one of WWE’s top babyfaces. His pursuit of the WWE Title has triggered a rivalry with Sheamus, a tough Irishman. Sheamus won the Money in the Bank briefcase in June, so he can get a title shot whenever he wants.

-Why: Neither man wants the other to be a title contender, nor do they particularly like each other. They fought last month at Battleground in a match that Orton won.

THE RYBACK vs. THE MIZ vs. THE BIG SHOW

-What: A triple threat match for the WWE Intercontinental Title.

-Who: The Ryback is a babyface who’s both really into positive thinking and working out. He won the Intercontinental Title in May, capturing his first singles title. The Miz is a heel who fancies himself a movie star despite the fact that he’s only really been in WWE’s terrible movies. The Big Show is either a good guy or bad guy depending on the week. His gimmick is that he is very big. Ironically, Big Show is a bigger movie star than The Miz, having played a key role in the 1998 hit The Waterboy.

-Why: This match was originally scheduled for last month’s Battleground show, but was postponed when Ryback had a bad staph infection. Miz and Big Show have both pursued the Intercontinental Title since the night after Ryback won it.

-Fun Fact: The Intercontinental Title has been defended 21 times in SummerSlam history, with the champion retaining a mere seven times and losing the belt two-thirds of the time.

BRAY WYATT and LUKE HARPER vs. ROMAN REIGNS and DEAN AMBROSE

-What: A tag team grudge match.

-Who: Bray Wyatt is a spooky Southern cult leader. He originally led the Wyatt Family, a trio of creepy Southern bad guys who attacked people – Luke Harper was one of his followers. Roman Reigns and Dean Ambrose are buddies, having joined WWE as two-thirds of The Shield – along with Seth Rollins – who also attacked people but eventually evolved into just being three buddies that really liked teamwork. Both groups broke up last year.

-Why: Bray Wyatt interfered in June’s Money in the Bank ladder match, costing Roman Reigns the briefcase and a guaranteed WWE Title shot. Reigns wanted revenge in a match at Battleground, but lost when Luke Harper returned to Wyatt’s side and interfered. So now Ambrose is reuniting with his best friend, though there have been teases that he may turn on him – mostly with them really over-emphasizing that they’re best friends on the shows leading up to SummerSlam.

WWE Tag Team Champions THE PRIME TIME PLAYERS vs. LOS MATADORES vs. THE LUCHA DRAGONS vs. THE NEW DAY

-What: A fatal four-way match (one fall to a finish) for the WWE Tag Team Championship.

-Who: The Prime Time Players are Titus O’Neal and Darren Young, the WWE Tag Team Champions, and they’re babyfaces. They won the titles in June from The New Day, who are any two of the three of Kofi Kingston, Big E (Langston) and Xavier Woods. They are heels, with typically Kingston and Big E wrestling and Xavier Woods shouting positive things at ringside in an obnoxious manner. The Lucha Dragons are Sin Cara and Kalisto, who joined WWE from NXT in March. They’re former NXT Tag Team Champions and good guys who wear cool costumes and wear luchador masks. Los Matadores are Diego and Fernando, a pair of guys from Puerto Rico who wear matador costumes and masks. They have a sidekick who is a mini who wears a bull costume.

-Why: All four teams want to be tag team champions. Apparently wins and losses don’t matter in this division, though, as all three challenger teams have alternated wins and losses on television over the past few weeks yet all get title shots anyway.

-Fun Fact: Despite existing continuously in some form for the entirely of SummerSlam’s existence, the Tag Team Title is the least-defended of the old-school championships. The belts have only changed hands four times in SummerSlam history, and the last time was in 1999. They haven’t even been defended since 2012.

STEPHEN AMELL and NEVILLE vs. STARDUST and KING BARRETT

-What: A tag team grudge match.

-Who: Stephen Amell is a Hollywood actor who stars on Arrow on The CW Network. Neville is a former NXT Champion and a high-flying wrestler. Stardust is a faced-painted weirdo who says crazy things in his interviews. King Barrett is an English brawler and the reigning King of the Ring. Amell ran afoul of Stardust on RAW in May, prompting Stardust to begin harassing him on social media.

Stardust also began a series of altercations with Neville in July. Neville had previously ran afoul of King Barrett, who he lost to to crown Barrett the King of the Ring in late April. Stardust confronted Amell on RAW earlier this month, leading to Amell attacking Stardust in the ring and demanding a match from Triple H.

-Why: Amell doesn’t like Stardust. Neville doesn’t like Stardust. Barrett doesn’t like Neville, and seemingly was placed into this match so they can hide a Hollywood actor in a tag team match so he doesn’t need to get too physically involved in the match.

KEVIN OWENS vs. CESARO

-What: A singles grudge match.

-Who: Brash prize-fighter Kevin Owens joined the main roster in May from NXT, where he was the champion, answering John Cena’s open challenge for the United States Title. Owens beat Cena cleanly in a non-title match at Elimination Chamber, then lost cleanly at Money In the Bank and Battleground. He soon ran afoul of the well-dressed Swiss technician (Antonio) Cesaro, who’s become increasingly popular since his tag team partner Tyson Kidd broke his neck in June, saying he didn’t want Cesaro to steal his spotlight.

-Why: Owens is jealous of Cesaro’s popularity, and seemingly doesn’t want the world to forget about him after losing to John Cena repeatedly. Cesaro just doesn’t like Owens and wants to prove that he’s better than him.

-Fun Fact: Owens is one of three former NXT Champions wrestling at SummerSlam – the others are Seth Rollins and Neville.

TEAM BELLA vs. TEAM P.C.B. vs. TEAM B.A.D.

-What: A triangle (elimination) tag team grudge match; eliminating a member of a team eliminates the entire team.

-Who: Team Bella is WWE Divas Champion Nikki Bella, her twin sister Brie, and Alicia Fox, who paired up with them in June in an effort to gain an advantage in the division. Depending on the week, they’re babyfaces or heels with seemingly no logic to it. Team B.A.D. is Naomi, Tamina and NXT Womens Champion Sasha Banks. Naomi turned heel in mid-April and joined up with Tamina in May, as both of them are vaguely associated with the Samoan Anoai wrestling dynasty in some way and want to see Naomi as Divas Champion. Sasha Banks joined them in July. They’re all heels.

Team P.C.B is Paige, Charlotte and Becky Lynch. Paige, a babyface, has been feuding with the Bellas since January, but kept losing because of the numbers game – which got worse when Fox joined Team Bella. Charlotte (Ric Flair’s daughter) and Becky Lynch joined Paige from NXT in July, giving her some much-needed back-up. Both of them seem to be title contenders, too. Paige and Charlotte are former NXT Womens Champions.

-Why: Stephanie McMahon kicked off a “Divas Revolution” in July, bringing in the three newcomers from NXT and theoretically putting Nikki’s title in jeopardy. However, there really hasn’t been much discussion of title shots, despite Charlotte submitting Nikki in a tag team match and Sasha beating her one-on-one on RAW.

DOLPH ZIGGLER vs. RUSEV

-What: A singles grudge match.

-Who: Dolph Ziggler is a secondary babyface in WWE, a guy who’s popular but not quite as popular as the really popular guys. (Alexander) Rusev is an NXT alumnus, who joined WWE’s main roster in early 2014. He was an unstoppable force until he ran afoul of John Cena, who beat him at WrestleMania 31 (and Extreme Rules and Payback) to take his United States Championship and turn Rusev into a run-of-the-mill midcard heel.

-Why: Girl problems. After losing to Cena at Payback in May, Rusev kicked his manager (and girlfriend) Lana to the curb. She started flirting with Ziggler in June, making Rusev jealous and beg her to come back to him. She refused and began a relationship with Ziggler before the end of the month, leading Rusev to pair up with Summer Rae…and creepily dress her exactly like Lana. It’s been a weird feud.