Rob van Zyl
How about this situation. I've lost all my yellow scientists.
If the yellow D8 is still available, may I choose its action?
Or even if the D6 is still available, I could choose it to deny my opponents. Correct?
No, this is incorrect.
The bonus action is optional, but the (primary) action is compulsory.
(ie. you can take a blue d8 and move the Sailor and then choose not to convert a crate into two food.)
You may not take a die if you do not take the (primary) action. (ie. you cannot take a yellow die if you have no active Scientists.)
After taking a red, yellow or blue die, you must move an explorer of that colour with (up to) 3 crates. (ie. the crates are optional, but the move is compulsory.)