Slap Battles R15 Rounds are the special ammunition used for the Blunderbuss badge challenge. They are sold by the Ammo Merchant near the tree area on the main island and cost 2 coins in the live October update.
You need Slap Battles R15 Rounds because the It’s Hip to Be Square challenge is built around shooting the attacking NPC waves with this ammunition. Buying the rounds is one of the steps between owning Shotgun and earning Blunderbuss.
Slap Battles R15 Rounds: where to buy them
Head toward the tree area on the main island and look for the Ammo Merchant. Interact with the merchant while working through the Blunderbuss route and choose the R15 ammunition.
The live price for Slap Battles R15 Rounds is 2 coins. Once purchased, return to the challenge area rather than spending the rounds in unrelated fights.
Do you need Shotgun first?
Yes. The Slap Battles R15 Rounds route belongs to the Shotgun prerequisite for Blunderbuss. Shotgun is the glove you need before starting the badge challenge.
If you do not own Shotgun yet, reach its 50,000 Slap requirement first. Buying ammunition without the required glove does not skip that progression.
What are R15 Rounds used for?
Slap Battles R15 Rounds are used to damage the NPCs that attack during the It’s Hip to Be Square challenge. The run has three waves and ends with a much stronger brute.
Normal bots take multiple hits, so treat the rounds as a limited resource instead of firing into empty space or distant targets.
How to save ammo during the waves
Group enemies when possible because Slap Battles R15 Rounds can damage more than one target when the shot catches a cluster. That is more efficient than isolating every ordinary bot and spending several rounds on each.
Keep moving while setting up those shots. Saving ammunition is useful, but standing still to create a perfect line can let the wave surround you.
What if you run out?
If you exhaust Slap Battles R15 Rounds before the final enemies are dead, the cleanest response is to reset the attempt and restock rather than hoping the badge will complete without the required damage.
Use the failed run to judge how many early shots you wasted and whether grouping the normal enemies would leave a better reserve for wave three.
Are the rounds for Heavy Weaponry?
No. Slap Battles R15 Rounds belong to the Shotgun challenge used to unlock Blunderbuss. Once Blunderbuss is unlocked, its Heavy Weaponry ability uses its own cannonball mechanic.
That distinction keeps the unlock ammunition separate from the ability you receive afterward.
Quick answer
For Slap Battles R15 Rounds, find the Ammo Merchant near the tree, pay 2 coins and use the rounds carefully across all three badge waves. Save enough for the final brute.
the ammo are challenge ammunition, so conserving them matters more than firing as fast as possible.
How to prepare before spending the rounds
Buy the ammunition immediately before a serious attempt rather than carrying it around while doing unrelated fights. That keeps the resource tied to the badge run and reduces the chance of wasting shots.
Use the first attempt to learn where enemies approach from and how quickly they bunch together. Once you know the flow, later runs become much more efficient because you can wait for clusters instead of firing at the first target you see.
Why grouped shots matter
The challenge is not just about accuracy. It is about getting enough value from every purchase to survive all three waves. Hitting several ordinary enemies in one line is much better than spending multiple isolated shots on targets that could have been grouped.
A careful attempt is better than burning through the special ammo early and reaching the final wave without enough shots to finish. Saving ammunition is useful, but standing still too long can let the wave collapse on your position.
