The Hempire cup is a mulitplayer event where players compete to produce the highest quality strain. Every week there are 1 - 2 events, which last roughly 2 - 3 days. During the hempire cup you will be given a new original strain, which you use to breed to the highest possible quality. Events will last for 48 hours where you will you have a specific number of breeds (27 tunable) per plant to try and attain the highest quality plant.
The key to performing well in the Hempire Cup is to level up the quality of your strains. When you level up the overall quality of each strain in the single player it increases the breeding results in the Breeding lab.
i.e. A level 3 quality Afghani will give you a bigger bonus than a level 1 quality Afghani.
2. Use the right type of strain during breeding.
The second strategy is to use the right type of strains. There are 4 strain attributes. Potency, Aroma, Pain, and Mood. All strains have Potency and Aroma, however they only have either Pain or Mood.
Indicas - Pain
Hybrids - Either Pain or Mood
Sativas - Mood
So the best strategy would be to use sativas with sativas, and indicas with indicas. Note however you will sometimes need to combine them to get the best results, but in the end you will need to use the same type to get the remaining attribute.
3. Use Legendary Buds
Legendary buds are like super strains. They can level up all 4 attributes.