1,790. The Difference Between a Conditional Get and...
Hilchos Geirushin 9:5
The difference between a conditional divorce and one that will only take effect after a certain time or after a certain action has been performed is as follows: a conditional divorce has already been given but it isn’t completed until the condition has been met. Accordingly, when the condition is met, divorce is effected provided that the get still exists; this is so even if it isn’t in the woman's possession. When the condition is met, the woman need not pick up or take possession of the get because it was already given to her for purposes of divorce. If she re-married before fulfilling the condition, she need not leave the second husband, as was explained in halacha 8:1. However, when it comes to a divorce that will only take effect after a certain time or after a certain action has been performed, the woman was not given the get for purposes of divorce. Rather, it is considered to be entrusted to her until the designated time arrives or until she performs the designated task. It is therefore necessary for the get to be in her possession at that time, or in a place designated for it even if it’s not her own domain as was explained in halacha 9:3, so that she can acquire it. It is only then that she is divorced by this get. If she re-marries before the designated time or before performing the designated action, she must leave the second husband and any children they may have had are considered illegitimate. This is because she’s still a married woman, as divorce has not yet been effected.
Hilchos Geirushin 9:6
Let’s say that a man gives his wife a get, saying, “This get is not effective unless you give me 200 zuz” or “You are not divorced unless….” In such a case, he is not considered to have given a divorce at all. This is because the get wasn’t given conditionally, nor was it predicated on her taking some action. The same is true in all comparable cases.