When tuned standard it can be played with these three bar chords:
Gb Db B
e|--------2----------------------9------------------------7----------------|
B|--------2----------------------9------------------------7----------------|
G|--------3----------------------10-----------------------8----------------|
D|--------4----------------------11-----------------------9----------------|
A|--------4----------------------11-----------------------9----------------|
E|--------2----------------------9------------------------7----------------|
When tuned flat it can be played with these three chords:
G D C
e|-------3------------------------2----------------------------------------|
B|-------3------------------------3------------------------1---------------|
G|--------------------------------2----------------------------------------|
D|---------------------------------------------------------2---------------|
A|-------2-------------------------------------------------3---------------|
E|-------3-----------------------------------------------------------------|
peronsally i think it sounds better tuned flat.
the chords are in the correct order for both and the strum pattern is pretty easy.