DYNASTY WARRIORS 9 Empires

Rarer gems and other items are obtained easier the higher the difficulty setting you have set and the higher level your character/turn number is. I got my first epic gem on Normal difficulty, but I'd highly recommend doing your playthroughs on hard as it seems to be the most reasonable difficulty to balance drop rates and playability (on Chaos you are spending 5 minutes just trying to kill an enemy officer and one wrong move gets you killed in one hit).

The main ways you can get gems are:
- From your spouse or sworn sibling during a stroll
- Killing enemy officers in battle
- Buying from the shop (not recommended)

I'd recommend obtaining the title 'One of a Kind' (level 5 sword & level 5 evil) or the title 'Foolhardy' (level 5 sword & level 5 scroll) as these allow you to get the Bandit military unit which you can equip pre-battle, the Bandits increase item drop rate so can be very useful for this RNG based achievement.