Put caps on trials taken from a block (case 27460)

[Researcher321]

Is it possible to randomly select a block, then randomly select a trial within the block, then randomly select another block and repeat the process until the participant has went through - for example - 3 trials within each block? This would mean that once a participant has went through 3 trials for one block, a cap is put in place so that they no longer receive a trial from that block.