Score counter for Skat
Ruby 1.9, 52 characters

Input via command line arguments. I'm assuming the error message when having duplicate cards doesn't matter, so it just complains about an eval/type conversion error.

p eval$*.uniq!||$*.map{|i|"..UOK#$&lt;.0D"=~/#{i}?/}*?+


Example usage:

$ ruby1.9 skatscore.rb 7A 8A 9A UA OA KA 0A DA 7L 8L 9L UL OL KL 0L DL 7H 8H 9H UH OH KH 0H DH 7B 8B 9B UB OB KB 0B DB
120

$ ruby1.9 skatscore.rb 7A 7A
skatscore.rb:1:in `eval': can't convert Array into String (TypeError)
    from skatscore.rb:1:in `&lt;main&gt;'