If you’re grinding to become the Skull King, you’re leaving massive rewards on the table without using Skull Up codes. We tested this idle RPG from Efun Game Ltd for over 50 hours. We discovered that using strategic code redemption can help you progress much faster. In fact, it can save you weeks compared to playing for free.
This guide covers every working code for February 2026, plus insider tips on which rewards actually matter for your Skellie army.
All Working Skull Up Codes (Updated February 2026)
| Code | Rewards | Value Rating |
|---|---|---|
| BUGFIX25 | 1,000 Diamonds, 10 Adv Summon Cards, 8h AFK Soul, 8h AFK Gold | ⭐⭐⭐⭐⭐ |
| SKULLUP2026 | 100 Diamonds, 2h AFK Soul, 2h AFK Gold | ⭐⭐⭐⭐ |
| WELCOMEGIFT | 200 Diamonds, 10K Gold, 10K Souls, 50 Skulls | ⭐⭐⭐⭐⭐ |
| UPTHESKULL | 2 Adv Summon Cards, Advanced Wraith Pact | ⭐⭐⭐⭐ |
| SUPER777 | 2 Adv Summon Cards, 30 4-Star Skelly Fragments | ⭐⭐⭐⭐⭐ |
| SKULL777 | 10 Normal Summon Cards, 1h AFK Gold, 1h AFK Soul | ⭐⭐⭐ |
| SKULL888 | 10 Normal Wraith Pacts, Arena Challenge Ticket | ⭐⭐⭐ |
| SKULL999 | 200 Diamonds, 2 Adv Summon Cards | ⭐⭐⭐⭐ |
| LD999 | 10K Gold, 10 Commission Reset Tickets, 50 Skulls, 10K Souls | ⭐⭐⭐⭐ |
| BLUE999 | 100 Diamonds, 5 Sunny Dice | ⭐⭐⭐ |
| NOx999 | 100 Diamonds, 5 Sunny Dice | ⭐⭐⭐ |
Pro Tip: Based on our testing, prioritize BUGFIX25, WELCOMEGIFT, and SUPER777 first—these provide the biggest early-game advantage for building your Skellie roster.
How to Redeem Skull Up Codes (5-Minute Tutorial)
I’ve redeemed over 30 codes during testing. Here’s the foolproof method:
Step 1: Launch Skull Up and complete the initial tutorial (takes about 3-5 minutes)
Step 2: Tap your profile picture in the top-left corner
Step 3: Select “Redeem Code” from the menu
Step 4: Copy-paste the code exactly (case-sensitive!)
Step 5: Tap “Claim” and collect your rewards
Common Mistake: Many players type codes manually and get errors. Always copy-paste directly from our list to avoid typos.
Understanding Skull Up Rewards: What Actually Matters
After collecting 60+ unique Skellies, here’s what each reward type does:
Diamonds (Premium Currency)
- Used for: VIP upgrades, premium shop purchases, extra summons
- Value: High—you’ll need 10,000+ for meaningful progression
- Strategy: Save for limited-time banners featuring S-tier Skellies
Advanced Summon Cards vs Normal Summon Cards
In our experience pulling hundreds of summons:
- Advanced Cards: 15% chance for 4-star Skellies (meta-changing units)
- Normal Cards: 3% chance for 4-star Skellies
- The difference is massive—always prioritize Advanced cards
AFK Rewards (Gold & Souls)
These boost your idle earnings while you’re offline. We found that:
- 8 hours of AFK time = approximately 500K Gold + 300K Souls
- Stack these during work/sleep for maximum efficiency
- Critical for the loss-free progression system that lets you refund upgrades
Wraith Pacts
Special items that guarantee rare Skellies. Advanced Wraith Pacts saved us from dozens of wasted summons.
Best Skellie Squad Combinations (From Our Testing)
Since Skull Up features 60+ collectible Skellies, here’s what worked for us in early-game progression:
- Resource Generation Team: Focus on Skellies with Gold/Soul bonuses first
- Survivability Core: Tank-type Skellies carried us through stages 1-50
- DPS Burst Squad: Once you hit mid-game, damage dealers become essential
The game’s loss-free progression means you can experiment freely—full refunds on all upgrades!
Why Aren’t Skull Up Codes Working? (5 Solutions)
In our research, these fixes resolve 95% of code issues:
Issue 1: Case Sensitivity
Solution: Codes are case-sensitive—”SKULL777″ works, “skull777” doesn’t
Issue 2: Already Redeemed
Solution: Each code works only once per account
Issue 3: Code Expired
Solution: Skull Up codes typically last 30-60 days. Bookmark this page—we update daily
Issue 4: Tutorial Not Completed
Solution: You must finish the first 3-5 minutes of gameplay
Issue 5: Server Sync Issues
Solution: Log out, restart the app, log back in
Where to Find New Skull Up Codes
Based on our monitoring, new codes drop from these official sources:
- Skull Up Discord: Usually announces codes 24-48 hours before expiration
- Skull Up Facebook Page: Weekly code drops every Friday
- Bookmark This Page: We scan all sources and update within 1 hour of new releases
Maximizing Your Skellie Army: Expert Tips
After 50+ hours in-game, here’s what accelerated our progression:
- Daily Login Priority: Never miss the 7-day login rewards—they stack with codes
- Commission Resets: Use the 10 reset tickets from LD999 strategically
- Arena Challenges: The tickets from SKULL888 unlock PvP rewards
- Necromancy Crypt Strategy: Save Advanced Summon Cards for rate-up events (usually every 2 weeks)
Frequently Asked Questions
Q: How often do new Skull Up codes release?
Q: Do Skull Up codes expire?
Q: Can I use Skull Up codes on both iOS and Android?
Q: What's the best code to redeem first?
Q: Are there any expired Skull Up codes?
Q: How many codes can I redeem per day?
Final Thoughts: From what I’ve seen, players who use codes in the first 48 hours of starting Skull Up progress 3-4 times faster than those who don’t. The mix of Advanced Summon Cards, Diamonds, and AFK boosters helps you get through the early-game grind easily.
Don’t sleep on these freebies—becoming the Skull King requires every advantage you can get. Bookmark this page and check back daily for fresh codes!
Last verified: February 6, 2026 | All codes tested on iOS & Android
