Tomorrow will mark the first time recreational marijuana use is legal somewhere in the United States. For residents across Colorado, it will no doubt be a happy day. The decision to legalize the drug was decided publicly, with 65 percent of voters wanted the drug to be legal, and Washington expected to similarly lift bans in the spring.

The new Colorado laws aren’t entirely lax. They still govern issues like who is allowed to use marijuana, who’s allowed to sell it, and where use is allowed. Here’s everything you need to know about legally, recreationally using marijuana in Colorado (as of tomorrow):

1. You Can Legally Purchase Pot Only From State-Licensed Retailers Or Medical Dispensaries

About a dozen retailers plan to open in Denver tomorrow, and about 20 more will open in other areas of the state. Initial demand is expected to be so high that retailers may run out of stock tomorrow. Of the more than 500 existing medical dispensaries in Colorado, the only businesses allowed to apply for retail licenses, only only 136 have applied for licenses to date. Likewise, individuals cannot sell the drug. You can share up to an ounce with another person, as long as that person is legally allowed to have it and as long as no money changes hands.

2. Marijuana Use Is Only Allowed In Certain Areas

Its use will remain illegal or will soon revert back to being illegal in certain towns that choose to ban the drug. Additionally, like smoking cigarettes, smoking marijuana is not allowed in many work and public places, as covered by the Clean Indoor Air Act. Private residences and specified hotels will be the major allowable places. Also keep in mind that smoking will remain illegal on federal property, such as some parks and resorts.

3. You Must Be 21 Years Or Older To Buy Or Use Marijuana

Anyone under 21 caught using or possessing the drug is still subject to fines and jail time. Across the state, repercussions could be lenient for those under 18, who may be sent to juvenile assessment centers rather than jail. And in Denver, individuals aged 18 to 20 caught with an ounce or less would receive only a fine, similar to a parking ticket. Possession would not be considered a criminal offense.

4. You Can Only Buy A Certain Amount

People over 21 with a valid Colorado ID can purchase up to an ounce of marijuana from a retailer. Nonresidents can purchase only a quarter of an ounce.

5. You Can Buy It In Different Forms

Most pot merchandise is meant to be smoked, but some retailers offer a variety. Some sell edible products like brownies, cookies and carbonated beverages. Others sell cannabis oil, meant to be used with vaporizer pens similar to electronic cigarettes.

6. You Can Only Make Purchases With Cash

Marijuana is still completely illegal under federal law. Credit cards, debit cards and checks are all subject to federal regulations and are therefore unacceptable at legal marijuana dispensaries. Some speculate that this will change in the future if the U.S. Treasury slackens laws, according to NBC News.

7. Expect To Be Taxed Like Crazy

Retail pot will have a 25 percent state tax, on top of the usual state sales tax of 2.9 percent. Colorado expects the tax to bring in $67 million per year and plans to use $27.5 million of it to build schools, according to CNN. Those buying marijuana for medical reasons will not be subject to the additional tax.

8. You Cannot Bring Marijuana Across State Lines

The federal government decided not to challenge Colorado’s state marijuana law, but it is still considered an illegal substance elsewhere in the country.

9. You Can Get A DUI After Using Weed

State law prohibits drivers from having 5 nanograms or more of THC in their systems. Otherwise, drivers can be ticketed for impaired driving. Advocates of the drug say the THC limit is too low, as regular and medicinal users may have this amount in their system while still being essentially sober enough to drive. Officials warn that using marijuana and alcohol can intensify the effects. Additionally, as with alcohol, marijuana is subject to open container laws and cannot be anywhere in the car except the trunk.

10. You Won’t See Many Advertisements

As part of the unofficial agreement for the federal government to look the other way, Colorado law prohibits marijuana stores from advertising anywhere children are likely to see it, according to USA Today.

11. Marijuana Quality Will Improve

Legalizing the substance will lead retailers to compete with each other for the best product. Experts predict that quality will rise and that potentially dangerous marijuana will be nearly or fully eliminated.

12. You Can Grow Your Own

You can grow up to six marijuana plants in your home, as long as they are enclosed and locked. Again, you can share your stash with other adults as long as no money changes hands.

13. Colorado May Become A Tourist Hot Spot

Much like Amsterdam, Colorado could be the place to visit for stoners, which could boost the state’s economy.

14. Jails Will Be Roomier

There have been 210,000 marijuana-related arrests in Colorado in the last 25 years, a figure that will plummet in coming years. That means law enforcement and criminal justice efforts can focus on bigger issues.