ILLEGAL: C b1-a3 on turn 3:
There was no C on b1. The piece on b1 is a Q.
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For diagnostic purposes, here is the full movelist:
1. P g2-g4 
1... p f7-f5 
2. B f1-g2 
2... p c7-c6 
3. C b1-a3 
3... b d8-b6 
4. P f2-f4 
4... b b6-g1 
5. Q h1-g1 
5... p b7-b6 
6. P g4-g5 
6... p e7-e5 
7. P f4-e5 
7... r e8-e5 
8. S e1-e3 
8... r e5-e3 
9. Q g1-e3 
9... q g8-e6 
10. Q e3-h3 
10... b h8-g8 //Conversion
11. N a1-b3 
11... q e6-d6 
12. P c2-c3 
12... q d6-a3 
13. P b2-a3
In case there is a bug in the code, the settings file can be edited at /play/pbm/play.php?game=Cetina+Random+Chess&settings=asymmetric&submit=Edit