The rules say that the game ends immediately as soon as there are enough Age IV symbols in the player areas. Does this mean the player looses the rest of their actions for their current turn?
In our last game someone managed to hit the Age IV symbol count by finishing the research on a card. We played it so that the game ended right then and the player, who was a bit miffed, lost all their actions.
If we played it correctly it opens some interesting strategies...
I don't know what the designer's intent was but I think that from the rules as written "immediately" means "immediately".
So if a card with the Age IV icon had completed the research time and the last cube was removed from the card, then that might trigger the end of the game (depending how many other Age IV icons are out). The current player would not get to perform any actions at all.
Rules as written, the active player couldn't even take back that card into their hand because you can only do that at the end of the Development Phase. By then it's too late, the card has already become an active Technology.
Page 4 of the rules, Development Phase wrote:
At the end of the Development Phase, the active player
may take back in her hand any or all of her Technologies
Page 6 of the rules, The End of the Game wrote:
As soon as enough Age IV symbols are present in the
player areas, Age III ends and the game ends immediately.