Yes, you get gold just by playing. In single player:
- You get gold by playing a quick match (both winning and losing)
- You get no gold for the tutorial match.
- You get gold once for each trial you win. Repeated trials give nothing.
Gems can only be bought with real money and can be used to:
- Unlock the other starter decks.
- Buy the weekly face-up offers. These are six random scrolls (2 common, 2 uncommon and 2 rare) that refresh weekly just for you.
Gems can not buy anything that can't be bought with gold, and to buy scrolls and scroll packs you can only use gold.