From Enter the Gungeon Wiki
+1 Bullets is a passive item.
Bluer Guon Stone - If the player has Blue Guon Stone, the size of the Guon Stone is increased.
Clearer Guon Stone - If the player has Clear Guon Stone, it grants immunity to poison, fire, and electricity.
Friend to Gun and Bullet - If the player has Potion of Gun Friendship, while it is active, a copy of the player's current gun appears and automatically fires at nearby enemies.
- The copy of the held gun fires faster than normal but with reduced damage, especially if it is a rifle-style weapon.
- This synergy affects the Prize Pistol while playing Winchester's mini-game, and the shots fired by the copy do not count against the player's allowed tries.
- If the player drops Potion of Gun Friendship while the synergy is active, the copy gun is permanent. This can be done repeatedly to amass a large amount of orbiting guns. (This glitch appears to be patched)
- The copy gun carries over to the Past.
- The copy gun can reveal secret rooms (unless it is an infinite ammo weapon or other kind of weapon that cannot normally reveal secret rooms).
- The copy gun fires all types of the guns bullets at once (e.g. fires all three levels of Polaris at once).
Greener Guon Stone - If the player has Green Guon Stone, 20
appears whenever Green Guon Stone heals the player.
Nailed It! - If the player has Nail Gun, its nails deal triple damage.
Oranger Guon Stone - If the player has Orange Guon Stone, it grows in size, fires more frequently, and deals more damage.
Pinker Guon Stone - If the player has Pink Guon Stone, enemies that damage the player become temporarily charmed.
Pistol Machine - If the player has Machine Pistol, its shots pierce enemies and are connected with electricity.
Redder Guon Stone - If the player has Red Guon Stone, the Guon Stone's size is increased and the player will gain a yellow glow and stat increase similar to that of the Macho Brace for a short time whenever the Guon Stone blocks a bullet.
Reinforced - If the player has Lower Case r, it spells out BULLET+1 when fired.
Whiter Guon Stone - If the player has White Guon Stone, the size of the Guon Stone is increased.
- This item could be a reference to common magic items from Dungeons and Dragons. For example, a +1 sword would add one bonus damage and have one better chance to hit on attack rolls, thus being "1 better than (a) normal" sword. The flavor text supports this, '+1 To Bullet' as opposed to '+1 to hit' or '+1 to damage'. In previous versions of Dungeons and Dragons, a well crafted but non-magical weapon was called a Masterwork weapon, giving further evidence to this reference through the item description.