These chords are just about 100% accurate. I determined them by watching multiple videos 
of GBS performing this song live.

Capo 1st fret, Standard tuning

Intro:
D (xx0232@1)A (x02220@1)G (320003@1)x2

Verse 1:
DHer (xx0232@1)brother can be difficult

AA (x02220@1)blessing and a curse

GBut (320003@1)a livin' life without one

Is somethin' far worse

DTogether (xx0232@1)in fraternity

AA (x02220@1)sentence set for life

GLaced (320003@1)with petty rivalries

D (xx0232@1)          AAnd (x02220@1)ready for a fight

Verse 2:
Together in fraternity
A sentence set for life
Laced with petty rivalries
And ready for a fight

Verse 3:
When nothing's ever left unsaid
The battle lines are drawn
Promises are broken
Attack again at dawn

Verse 4:
Weapons drawn and ready
And who will fire first
Hands strong and steady
Hit exactly where it hurts

Chorus:
        G (320003@1)                  DBut (xx0232@1)you never lead a love so rare
    G (320003@1)                  D (xx0232@1)  AYou (x02220@1)never lead a love so long
Em7/B             G/f#    GRemember (320003@1)that the life we share
    AIs (x02220@1)nothin' but a song

Verse 5:
So you put on a happy face
For everybody new
But the closest to your heart
So rarely get the best of you

Verse 6:
A moment's contradiction
And the bickering's begun
Daughters after mothers
And fathers on their sons

(Chorus)

Bridge:
 Bm (x24432@1)                 A (x02220@1)                   GAhhhhhhhhhhhhhhhhhhhhhh, (320003@1)Ahhhhhhhhhhhhhhhh, Ahhhhhhhhhhhhh (x4)

(Chorus)

Outro:
D A G (x2)
Bm A G