I’ve downloaded a lot of free-to-play games this past week and started tapping my way through them. Free-to-play games can be a minefield with how they coax players into paying for content or bonuses, so let’s set some guidelines of what to be careful of when picking a free-to-play game.

1) Two or three forms of in-game currency

Any more than three forms of in-game currency usually means that players will get nickeled and dimed with micro-transactions. If you have five or six forms of currency, you’ll always be short with at least half of these currencies and you’ll be goaded into using real-world money to purchase virtual money.

Of course not all currency is created the same. Last week’s AdVenture Capialist has far more than three forms of in-game currency, but realistically, there’s only one form of currency that matters: bucks. If you can ignore—or mostly ignore—all but one or two forms of in-game currency, you’ll do fine.

2) Few videos

Watching videos for power ups is okay, so long as you spend more time playing the game than watching videos. If you’ve played free-to-play games, you’re used to seeing in-game ads for other games, products, or services. This should be optional. Videos shouldn’t interrupt the game flow, rendering the game unplayable.

3) Continues without spending in-game currency

Energy that you gain over time doesn’t count when I say continuing without spending in-game currency. There are some games that make you pay for power-ups, boosts, and continues with the same currency, and most of them have an in-game store that allows you to buy this virtual currency with your real-world cash.

4) A fair and balanced reward system

There are free-to-play games that award moderate rewards for success, while doling out brutal punishment for failure. You’ll never get ahead unless you spend money, and that defeats the purpose of a free-to-play game—from a consumer’s standpoint.

5) Competitive without spending

You don’t have to win every match—what’s the challenge in that—but you should be competitive without having to spend money in a game. There are a lot of free-to-play games that insist you spend money just to win a match, and that’s unnecessary.

6) Spend time not money

This guideline plays off of guidelines three through five, and it’s really the golden rule for free-to-play games. You should always have the option to spend time away from the game rather than spend money when accomplishing something.

I get that developers want—or need—to get paid but they should tempt players with bonuses that they want rather than force them to buy bonuses they need in order to play the game. Time instead of money is usually a good route. Impatient gamers may spend the occasional dollar, but you don’t penalize patience.

Thanks for your patience. With that out of the way, let’s get to some game reviews.