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Underdog promo code: SPORTSLINE for $100 in Bonus Entries

Here's a closer look at the latest Underdog promo code SPORTSLINE, which gives new users $100 in bonus entries, as well as a review of the app

ByBrandon Gustafson·Published: Oct 08, 2026 8:11PM ET·15 min read

Daily fantasy sports (DFS) have exploded in popularity in recent years, with no shortage of apps and sportsbooks offering contests for their users. One such platform is Underdog, and we'll dive into the app, including how to sign up and claim the latest Underdog promo code for $100 in bonus entries after spending $5.

The latest Underdog promo code SPORTSLINE nets new users $100 in bonus entries after they play $5, and is perfect for the 2026 NFL season.  

*Drafts-only and Predictions-only states excluded; Unavailable in NV  

While Underdog's flagship offer is an appealing one, it also provides a couple of alternatives for new users who want to go in a different direction. The first is a 50% deposit match worth up to $1,000, with the details of the offer outlined below.

Last but not least is Underdog's other secondary offer. New users who play $5 worth of entries receive five free RIPS pack worth up to $750. The details of that offer are outlined below.

Here's how the latest Underdog promo code compares to Dabble's offer and the promo code necessary to claim it.

Underdog gives users $100 in fantasy bonus entries after playing $5, while Dabble also hands out $50 in lineups after the same initial wager.

Underdog is available in 40 states and Washington D.C., and most locations require you to be 18 years or older to sign up.

Some states have different requirements, however. Alabama and Nebraska, for instance, require you to be 19 years old to sign up, and you must be 19 in order to play some games in Colorado. The minimum age in Arizona and Massachusetts is 21 years old to use Underdog. 

Those looking to sign up and claim the Underdog promo code can follow these steps. 

1: Click "Claim Bonus" on this page or on the affiliate link to be taken to Underdog Fantasy.

2: Click "Sign Up" and you will be redirected to Underdog's main page. Once there, click "sign up" again and enter all required information, as well as the promo code "SPORTSLINE," which may be filled in automatically. Ensure you are of legal age in a state in which Underdog legally operates.

3: Make your first deposit of at least $10 using an accepted payment method

4: Choose your promotion and proceed accordingly

I've gone through signing up with Underdog and utilizing its latest promo code and have played several different contests and formats. Here's what I found. 

Claiming the Underdog promo code is easy enough. Once you make an account, deposit at least $10 into your account. Then, you can choose between a 50% deposit match or receiving $50 in fantasy bonus entries after playing $5. 

Underdog delivers one of the smoothest and most user-friendly experiences in the daily fantasy space. The app is incredibly easy to navigate, with lightning-fast load times and a clean, modern design that makes it simple to find what you're looking for — whether you're placing Pick'em entries or joining a Best Ball draft.

What makes Underdog really shine is how effortless it feels. You can build an entry in under a minute, and everything updates in real time without any lag or clutter. It's clear the platform was built with speed and simplicity in mind. Whether you're into player props or season-long fantasy formats, Underdog Fantasy gives you a fast, fun, and reliable platform to play on.

The Pick 'Em game is a standout feature. It revolves around choosing "Higher" or "Lower" on projected player stats across a wide range of sports. From passing yards and touchdowns in football, to home runs and strikeouts in baseball, to birdies in golf and points or assists in basketball — there's always something on the board. The variety of sports and stat categories keeps things fresh, and the ability to mix picks from multiple games or leagues adds a fun layer of strategy.

Underdog also offers Best Ball drafts, which are perfect for fans who love the excitement of drafting but don't want the weekly grind of managing a lineup. You draft once, and your best players are automatically slotted into your lineup each week. It's especially popular during football season but is now expanding into other sports as well.

Champions is another interesting format that, like Pick Em, revolves around deciding if players will go higher or lower than certain stat lines. Once you make your picks, you compete against other users to earn "Champions Points," with the winner earning the most points.

The Underdog app needs little improvement for me. It's great, clear and organized. If I'm going to give any feedback, I would say that it could stand to have better lines relative to sportsbooks. That's standard for DFS apps, but that would help set Underdog apart even more. 

Yes, Underdog is legal as one of the largest DFS platforms available. It is available in 40 states and Washington D.C. and can be downloaded via Google Play and the Apple App Store. Users must be 18 or older in most states, but the legal age for Alabama and Nebraska is 19 years old, and Colorado requires you to be 19 years old for certain games. Users must be 21 or older in Arizona and Massachusetts. 

Underdog takes account safety seriously as well and offers tips for keeping your account safe that can be found on their responsible gaming resources page. 

Underdog offers its users a variety of games to play, and you can use the latest Underdog promo code to enter these contests. 

In Best Ball, only your top scorers of the week at each spot are designated as "starters" and account for your score. This means users don't have to set their own lineup – just draft a team, and your top scorers are all that matter. There's no stress of a player having a monster game while sitting on your bench. 

These drafts are conducted through a "snake" draft, meaning the user with the first pick of one round would have the final pick of the next round, the second pick would then have the second-to-last pick in the following round, and so on. In order to ensure all picks are made before the start of the season, there's a pick clock with different times and rules depending on the time of day as well as how close to the beginning of the season you are. This can also defer depending on the sport you're drafting for. 

The entry fees, prize pool, roster size, number of entrants, number of entries per user and scoring are all described on the information page for that specific contest. These can all change depending on the contest you're entered into. When the season ends, the prize pool will be distributed to the highest scorers based on the allocation designated for that specific contest's rules. 

In Battle Royale formats, entrants select players through a snake draft, which, as noted above, is where the first pick in one round would then select last in the following round, the second pick in one round would draft second-to-last in the next round and so on. The size of each snake draft may vary between Battle Royales, and contest details as far as prize allotment, group size, player pool and slate size all vary by contest. 

Unlike most snake drafts where you only compete against those in your draft/group, you're also competing against every snake draft group entered into that week's contest. That means some teams will share certain players. Your score will be matched up against every score in the contest rather than only against people in your specific group, and at the end of the week, the entrant or entrants with the highest scores are awarded prizes based on the contest's pool allocation.  

Champions is a format where players create a roster of 2-8 athletes from at least two different teams. Users then go athlete-by-athlete, predicting whether those players will go Over or Under certain statistical benchmarks. Once you submit your team and selections, you're entered into a tournament with other players, and the user with the most "Champions Points" by making correct picks is the winner. The final amount that participants win depends on how they perform relative to other players in their tournament, and prize pools are explained when you join a tournament and make your selections. 

One popular format that Underdog has is Rivals, which is a head-to-head competition between two players in a particular statistical category like points, goals, yards, etc. Most Rivals competitions will have an adjustment, such as LeBron James (+2.5) points against Kevin Durant. That would mean a Win for James would be if he scored more, equal, or two fewer points than Durant did. For Durant to be the winner, he needs to score three or more points than James. Not all Rivals contests will have adjustments, though, such as goals for Connor McDavid vs. Nathan MacKinnon. If neither score, it's a tie or void. 

Underdog also offers Flex payouts, which is where users can add more legs to their entries for greater payout multipliers. This also allows for users to still get a payout even with multiple incorrect picks. And if any legs are ruled as a tie or void, the entire entry moves down to the next eligible entry slot. You can learn more about Underdog's payout multipliers and other Flex rules in the table below.

Placing traditional wagers on college football isn't available in many states where fans are passionate about the sport. Underdog is a viable alternative for those interested; however, with different available contests, such as pick 'em contests. 

Underdog offers multiple banking methods for its users, such as credit and debit cards, Apple Pay and PayPal. Users can also link their banking accounts to their Underdog account. 

Underdog users are offered various promotions to utilize. These include profit boosts, stat slices, No Sweat Tokens where your stakes are insured if you lose, deposit bonuses and referral bonuses if you refer a friend to sign up and they do.  

One popular promotion that Underdog offers is called Vulture Protection. This is for football contests. Underdog defines a Vulture as "a rushing TD scored by a player who is NOT a Designated RB. When this TD is scored, the designated RB is considered to have been Vultured."

For example, if you roster Ravens running back Derrick Henry and his backup, Justice Hill, gets the score instead, the backup would have "vultured" the star running back's touchdown. If you select a "Designated RB" to score a touchdown, you can receive Vulture Protection. That means if someone besides your Designated RB scores a touchdown and that's your only losing selection of the day, your entry is "rescued" and you receive a promo in the lobby the next day. 

Does Underdog have promos? 

Yes, Underdog offers promotions both for new and existing users. The latest sign-up promotion gives new users $100 in bonus entries after they play $5. 

What is the best bonus code on Underdog Fantasy? 

Using the promo code "SPORTSLINE" allows new users to grab $100 in bonus entries after they play $5.

How can I get bonus funds at Underdog?

Underdog's latest new-user offer is for $100 in site credit after playing $5. Additionally, Underdog will occasionally offer free picks for its users, which can net players payouts with no investment should they win. 

Does Underdog give free picks? 

Yes, Underdog offers free picks and contests for users. 

Is Underdog app legal?

Yes, the Underdog app is legal in 40 states and Washington D.C. Most states require users to be 18 years or older, while the legal age in some states is either 19 or 21. 

Is Underdog payout instant?

Underdog pays out users once a contest is complete, though some games are subject to review. But payouts occur once a contest is settled. 

Can you have multiple Underdog accounts?

No, Underdog does not allow users to have multiple accounts. Underdog will terminate accounts and withhold or revoke prize money should a user try to utilize multiple accounts with the platform or collude with other participants.

Written by Brandon Gustafson

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