In Task Builder 2 it is not possible, for example, to add two ‘Randomise Trials’ components to a task. I can get around this by creating a custom randomiser component with the same functionality as the ‘Randomise Trials’ component. My custom component and a ‘Randomise Trials’ component work perfectly well together, indicating that there is no reason in principle why it should not be possible to add two ‘Randomise Trials’ components to a task. A common use case is where we have n trials of two types and we wish to pseudorandomise trial order by (1) dividing the trials into blocks and randomising trial order within blocks with the two types occurring equally often in each block and (2) randomising trial order within conditions, by which I mean determining at random which of the n/2 trials of each condition ends up in each of the positions assigned by step (1) to trials of that type. Step (2) ensures that trials originally located in block i do not remain together in block i, but can end up in any block, while still allowing that the two trial types occur equally often in every block. Steps (1) and (2) can each be achieved using a ‘Randomise Trials’ component, but the fact that two ‘Randomise Trials’ components cannot be added to a task makes this use case unachievable except by creating a custom randomiser component that mimics the ‘Randomise Trials’ component.