You don’t grow into a $25 billion industry without making up a few words along the way, and mobile gaming is no different.

This industry is overflowing with jargon and nonsense acronyms. Well, the days of you looking confused when the chief executive of a mobile-gaming startup corners you and starts yelling about “our poo” is over. We’re here with a useful lexicon to help you make sense of this crazy industry.

Let’s get to it.

Midcore

Midcore is a group of people who like games a lot but maybe don’t have enough time for them as they used to. It is a term that a lot of mobile developers use to indicate that they are making a “serious” game. It’s also the result of the rise of casual games for “casual gamers” as opposed to traditional console games for “hardcore gamers.” Developers have noticed that a lot of people, especially adults, come from hardcore-gaming backgrounds and they are looking for free-to-play experiences on mobile in their very limited free time. That’s the midcore audience.

Let’s use it in a sentence

“Our free-to-play mobile strategy game features a mature story and deep mechanics that midcore gamers are going to love.”

User acquisition

User acquisition is the process or methods by which games, typically of the free-to-play persuasion, entice consumers to download and try their game. You’ll read and hear this term a lot because it is probably the thing that mobile developers are thinking about the most. Examples of user acquisition include ads for games in other free-to-play games or those commercials you see on TV with Kate Upton. Oh, and we don’t write “user acquisition” on this website. We say “player” or “gamer acquisition.” That goes for the other examples of “user” you’re about to read as well.

Let’s use it in a sentence

“Our company just raised $1 million from venture capitalist firms to help us expand our user acquisition.”

DAU

DAU is an acronym that stands for daily active users. It is a number that denotes how active a game’s player community is on a day-to-day basis. For example, last year, publisher King’s Candy Crush Saga had 93 million daily active players.

Let’s use it in a sentence

“We’re keeping our DAU high by regularly adding new content.”

MAU

MAU is very similar to DAU, only it is for monthly active users. This is the number that most developers and investors talk about when referring to the health of a game.

Let’s use it in a sentence

“We’re investing in this developer because its games have 30 million MAUs, and we want to help take that to the next level.”

ARPDAU

More acronyms! This time we’re talking about ARPDAU, which stands for average revenue per daily active user. This is another number that represents the health of the game, but instead of talking about the audience size, it signifies how much that audience is spending.

Let’s use it in a sentence

“Our ARPDAU reached 10 cents after we implemented virtual hats into our game.”

ARPPU

ARPPU is a very common acronym in mobile-gaming circles. It stands for average revenue per paying user, and people actually say it out loud as “are pu.” While MAU is the key metric developers use to measure the size of their audience, ARPPU is how developers measure how well they are squeezing money from those gamers. It is just a technical way of saying how much money a paying customer spends on this game during a certain period of time.

Let’s use it in a sentence

“This game’s ARPPU is higher than many other games because the developer is using cutting-edge monetization tactics.”

Whales

Whale is a term that mobile developers (as well as social-game developers and casinos) use to refer to the small group of people who spend the most on a game by a wide margin. Most people don’t spend anything on a game, but a very tiny percentage will spend potentially hundreds of dollars. These gamers drive up that ARPPU, and they are important to the free-to-play ecosystem — although, their importance has shrunk as developers have learned to get more money from other players as well.

Let’s use it in a sentence

“The top whales in this game have spent more than $500 on improvements for their character.”

Dolphins

Staying with the aquatic animal theme, Dolphins are the middle-of-the-road spenders. These are players who maybe spend $10 a month on a game when they get their paycheck. They are also of growing importance as mobile games get better and more people are willing to spend money.

Let’s use it in a sentence

“We’ve added several new items in our store to better serve our dolphins.”

Minnows

I bet game developers love using the “plenty of fish in the sea” metaphor. Minnows are the lowest rung of gamers that still spend money. They only put around $1 into a game, and that is it.

Let’s use it in a sentence

“We don’t want to ignore our minnows, so we are holding a sale for items that many of the top-spending players already have.”

Freeloaders

I guess we’ve run out of fish. Freeloaders are the vast majority of gamers who don’t spend anything on free-to-play games. Developers often focus a lot of effort on trying to turn these players into paying customers.

Let’s use it in a sentence

“We’ve added new video advertisements to make more money from our freeloaders.”

Conversion rate

Conversion rate is a number that usually measures two things in mobile gaming. First, it tracks what percentage of people who see a player acquisition ad go on to download and play the game. Second, it measures the ratio of freeloaders that end up spending money.

Let’s use it in a sentence

“Our conversion rate on our Facebook ads nearly doubled after we started running our television campaign featuring that swimsuit model.”