Open D tuning
The open D tuning is popular among guitar players who, for example, using a slide. (Not to be confused with Drop D tuning.)
When you retune your guitar it’s important that you turn the tuning pegs in a direction that decrease the string tension and not the opposite.
To get the open D tuning on your guitar you tune it like this: D A D F# A D.
These are some of the chords you could play in open position when using this particular tuning.
Movable one finger shapes
All you have to do is to lay your fingers over the four highest strings and avoid playing on the two lowest strings. As the pictures illustrate the D chord could be played with all open strings.
The shapes are movable, so if you move the fingers two steps up the fretboard from G major you will get an A major.
All common major chords in open D:
C: XX 10 10 10 10
Movable form for slash chords, some examples:
In the style of Keith Richard
Keith Richard uses open tunings including Open D. If you're interested in typical chords, here are some (all used in "Street Fighting Man"):
C: 10 10 10 10 10 10
F/C: 10 12 10 11 12 10