My wife and I played our first game of Roma the other day and came up with several rules questions. All of them are addressed in the forums except this one: Why do some cards, for example Turis and Templum, have an activation cost when they do not require a die to be activated (at least as we understand the card text/rules)? Must this cost be payed when the effect of the card is evoked?
My first thought at first there might be a card that converted an in-play card to gold or something, but there doesn't seem to be such a card.
What do you mean by an "activation cost"? All cards have a cost to play (the Gold) and a defence value (the Shield). Turris and Templum do not require a die to activate them (that is the die with an X in the upper corner).
The only time the gold must be payed is when the card is first played from your hand.