Camping and Travelling mechanicIt's a two-sided 'blank state' that some kingdom cards have. At the start of your turn, choose which side you want ('Camping' or 'Travelling'), and it stays that way for the rest of the turn. Choose which mode you need to be in.
Some example camp/travel cards to demonstrate the possibilities:
Historian - Action, $5 cost.
If you're Camping, +3 Cards. If you're Travelling, draw until you have 7 cards in hand.
You can do cards with two play modes to choose from each turn. Do you need your draw to be smithies or draw to 7 this turn? Sometimes you want to flip modes during the game, other games you want to stick to one or the other.
Prospector - Action Reserve, $5 cost.
If you're Travelling, gain a card to your hand costing up to $6. Put this on your Tavern mat.
-
When you flip to Travelling, you may discard this from your Tavern mat.
Slow and spiky. After you play it, you have to spend a later turn Camping, then the turn after flip to Travelling to discard it off the mat.
Provisioner - Action, $8* cost.
+1 Card
+1 Action
If you're Travelling, + $2.
-
If you're Camping, this costs $3 less.
Only works in one mode, but it's more purchasable in the other.
Balance may be off, and the qualification for this contest may be too loose, but maybe this is still interesting.