The sturdy stick is an item used in the crafting of makeshift items.
A sturdy stick can be used in conjunction with a notched wooden plank to start a fire. To light a campfire, first ensure that fuel has already been added to the campfire, which will act as the kindling. The player must have the notched wooden plank and sturdy stick in their inventory. Right-clicking the campfire and selecting "Light Fire" > "Notched Wooden Plank + Sturdy Stick" will cause the player to attempt to light the fire, although there is a chance that they will fail, breaking/destroying the sturdy stick. If successful, the campfire will burst into flames, while the sturdy stick and notched wooden plank will be returned to the player's inventory.
Note that this method of fire starting can only be used for lighting a campfire and antique oven, and will not work for lighting a charcoal barbecue.
Sturdy sticks have an additional use as a fuel for fires, and last for 15 minutes if used this way. This is the lowest burning time of any item.
Sturdy sticks are crafted from planks using the saw (Right-click Wooden Plank, select Sturdy Stick). It can also be used to create a splint, tent kit and makeshift fishing rod.
Sturdy sticks cannot be found in the world and only obtained through crafting.
From newitems.txt (Project Zomboid directory/media/scripts/)
Type = Normal,
DisplayName = Sturdy Stick,
Icon = TZ_WoodenStick,
Weight = 0.1,