There are some great fireworks in Ultimate Equipment and Player Companion: Alchemy Manual. Jumping jenny’s, flame fountains, and so on. A lot of them can even do damage or cause effects, which is cool for adventures. But, sadly, they all have a very narrow range of character levels when they are useful, and that is both sad and limiting. While it makes sense for off-the-shelf fireworks, characters who are adventuring experts with explosives (alchemists in particular) are missing out on great, thematic, cinematic options by the non-scaling nature of fireworks.
So, given the season, we proudly present: The Pyrotechnist Discovery!
Pyrotechnist (Alchemist Discovery)
You can double the range (but not area) of any firework you use. When you set off a firework, you may expend one use of your bombs to add the bomb damage to any damage the firework does. You may not use any other talent that alters bomb damage when you do this. Also, any save DC of the firework uses its base DC or a DC of 10 +1/2 your ranks in Craft (alchemy) plus your Intelligence bonus, whichever is higher.
When you set off a firework, you can make a Craft (alchemy) check to focus the sounds and light from the explosion to specifically startle up to one creature per rank in Craft (alchemy) you have, no two of which can be more than 30 feet apart, all of which must be able to see or hear the firework. The DC of this check is the same as a Bluff check to feint the targets (make a single check and compare it to all the targets). Once you have attempted this ability, the DC to startle any creature who saw or heard the attempt goes up by +5 for 24 hours.
Additionally, you can alter the color, sound, and shape of fireworks in ways that have no effect on their range, size, or impact on the environment, but that can be used to convey concealed messages. Whenever you set off a firework you can convey secret messages (as the function of the Bluff skill) of up to 10 words by making a Craft (alchemy) check. Anyone who sees the firework can attempt to make a check to interpret your message, using Craft (alchemy) or Sense Motive, whichever of their skills has a lower bonus. If you have a chance to confer with a group for 5 or more minutes in advance about what message you will send them with fireworks, the DC for anyone else to understand increases by +20.
Finally, if you can cast spells or use alchemist extracts, you can always sacrifice a spell slot, prepared spell, or alchemist extract of 1st level or higher to cast snapdragon fireworks or pyrotechnics as a spell-like ability (using your caster level or alchemist level as the caster level, and calculating any save DCs as you do your spells or extracts).
This discovery can also be taken as a talent or feat by any character with a class feature that creates bombs.
People backing my Patreon also have the minor exclusive benefit of seeing what I did for “Greater Pyrotechnist,” a simple add-on advanced discovery! This is something new I am trying — the same free content for everyone, and a little something extra for my backers. Check it out for just a few dollars a month!