Additional Rules from the Rulebook
Costs are 1 coin lower for all purposes. For example, if you played Village, then Bridge, then Workshop, you could use Workshop to gain a Duchy (because Duchy now costs 4 coins due to the Bridge). Then if you played 3 coins, you could buy a Silver (for 2 coins) and an Estate (for 1 coin). Cards in players' decks are also affected. The effect is cumulative; if you Throne Room a Bridge, all cards will cost 2 coins less this turn. Costs never go below 0 coins. For this reason, if you play Bridge and then play Upgrade, you could trash a Copper (which still costs zero, even though you played Bridge) and gain a Pawn (which costs 1 after Bridge is played).
The Secret History of Bridge
In an article on Board Game Geek, Donald X. Vaccarino commented on the development of Bridge:
- I tried something like this in the murky past for the main set, and decided it was too strong. I had a weaker version that I later tried on Woodcutter (it only made the 2nd copy of a card that you bought in the same turn cheaper), but decided that was too confusing for the main set. A while later I had just stolen a card from the 6th set for the main set, and needed a replacement. This idea sounded like it might not be trouble after all, and in fact it wasn't. I then stole this from that set for this one when I needed another +Buy card.
- Bridge makes all cards cheaper, not just ones in the supply. This was to prevent problems in weird situations. I am not sure the kind of thing you'd need to get those problems will ever happen, but I knew that this way of doing it meant I was safe. This also allows some unusual combos to work.