Guitar vs Piano vs Organ

[Work over Talent]

Guitar players can strum their chords and do all kinds of tricks to keep their chords from sounding repetitive and boring. What would be the piano's and organs equivalent to strumming ? I mean block chords get pretty boring after a couple of bars with pianos they just sound stale and lifeless. What are some tricks to playing piano chords in interesting and unpredictable ways without throwing the listener off ? Scale runs and arps are a couple i know... but i dont wanna play the same ol arpeggios in every beat.

 

[scrapheaper]

Play different arpeggios then.
You can play block chords in a rhythm, like strumming but without the natural up/down strokes.
When I play a rhythm of block chords, I sometimes like to change the inversion of the chords for one or two beats in the pattern.
If you don't have a bass instrument you can play bass octaves in the left hand and alternate with right hand block chords in a two part rhythm.
Jazz players anticipate chords and play them half a beat early or late.
Or you can put single notes/ little melodic riffs inbetween the chords.

Keyboard instruments are a lot easier to create variation with because you have two hands, both of which can play separate rhythms- this is just a brief splurge of ideas, I could come up with more probably given time.