In every Pokemon game players want to train their Pokemon to be stronger, which is typically done with EVs. However, in Pokemon Legends Arceus there are no EVs. So if EVs are not around, then how can you make your Pokemon stronger? Does it matter which Pokemon you defeat? Instead of using EVs, you can make your Pokemon stronger by increasing their Effort Levels. Before you ask, the answer is no: you do not increase this by defeating other Pokemon. The only thing defeating specific Pokemon is useful for is completing Pokedex missions, or getting specific items.  

What Effort Levels do in Arceus is increase the stats of a Pokemon, and each stat has its own Effort Level value. Effort Levels are similar to EVs in this way. Effort Levels start at 0 and max out at 10, and it is possible to max out every stat on a Pokemon. This is something that is not possible with the EV system, where you have to make careful choices about how to spend your points.

When you catch wild Pokemon in Pokemon Legends Arceus you can check their Effort Levels by looking at their summary, and going to the stats page. You can also see a graph of a Pokemon's stats, and the area marked in blue shows how Effort Levels have improved each stat. To the right of the stats will be circles with numbers inside them: these are the Effort Levels.

Garchomp-Effort-Level-graph-Pokemon-Legends-Arceus

You can also check the Effort Levels of Pokemon inside your pastures. Whenever you have a Pokemon selected their stats are shown in the top right corner, along with their Effort Levels. Wild Pokemon will have randomly distributed Effort Levels, and Alpha Pokemon are more likely to have higher Effort Levels than normal Pokemon. 

Effort Level training in Pokemon Legends Arceus is also vastly different from EV training. If you want to learn how to maximize the Effort Levels on your Pokemon, check out my complete guide explaining everything you need to know.