Playing the Powerball with co-workers can be a fun bonding exercise with the people you work with every day. You purchase lottery tickets as a group with an agreement that you split the winnings if anyone wins.

It increases your odds of winning and lets you socialize with people at work.

If you actually win the thing, though, things could get hairy.

Five New Jersey construction workers had been buying lottery tickets together for years. When they finally won in November 2009, the man who actually purchased the winning ticket on his own tried to claim it for himself.

To make sure you’re protected, here’s what you need to know about playing the lottery with a group of co-workers or friends.

Name a leader

This person is responsible for collecting tickets, checking the results and handling all of the the tickets bought within the pool.

It should be someone responsible that everyone trusts. (Not Dave, who keeps borrowing your money but will totally pay you back next week).

Write a contract

It doesn’t have to be too complicated. Don’t waste (even more) money getting a lawyer to write a big, official-looking document. After all, your odds of winning are pretty close to zero.

Just make sure everyone is on the same page about how numbers will be selected, whether you’ll take the annuity or lump sum, how often you will play and how you are splitting the winnings.

Write that up and have everyone sign it.

Make copies of the tickets

This way, everyone knows exactly which tickets were bought through the group, lest someone decide to cook up a story about how they bought a winning ticket on their own.

If you win

Some states allow multiple winners to claim the same prize. For states that don’t, you can set up a trust to claim the money on behalf of the group.

That’s what 16 Manhattan colleagues did in May, and they each walked away with $1.65 million after taxes.

Oh, and those construction workers?

The other four sued, and even without a written contract or agreement, a jury ruled that the man had to split the winnings.

The lesson: Don’t try to take the money and run.