Can I sacrifice an Ancient Gear Castle with only one counter and one monster on my side of the field to tribute summon Ancient Gear Golem?
Ancient Gear Castle said:If you Tribute Summon a monster that includes "Ancient Gear" in its card name, you can substitute this card for a Tribute(s), if the number of counters is equal to or greater than the number of required Tribute(s).
So you would have to have enough or not remove counters at allAncient Gear Castle:
if the number of counters is equal to or greater than the number of required Tribute(s).
If you only have 1 counter, that means that you have (for instance of the case) 1 monster, if you have another monster plus this card, that makes it for 2 monsters "per say"Increase the ATK of each face-up monster on the field that includes "Ancient Gear" in its card name by 300 points. Each time a monster(s) is Normal Summoned or Set, put 1 counter on this card. If you Tribute Summon a monster that includes "Ancient Gear" in its card name, you can substitute this card for a Tribute(s), if the number of counters is equal to or greater than the number of required Tribute(s).