I've seen a few images on Pinterest (unfortunately all go through to dead links) that show people making the general shape of a weapon with expanding foam, then carving the excess off.

Here's an image I found (ignore the unsuitability of the wooden handle) :

A visual guide to making weapons with expanding foam

My experience with expanding foam is that it can go hard and crumbly. This to me sounds like it would make a poor material for LARP weapons.

Is this material durable, and safe enough to be used in this way?

I'm based in the UK, and I don't have a fixed LARP group.


You are exactly right, the material characteristics of expanded foam after it is cured are not suitable for LARPS weapons.

PU foam is, however, good for making props due to the ability to get it into a rough shape and then carve in the fine details. However to paint it and preserve you need to do some extra steps by adding layers of painter tape, and paper mache. After which you can then paint it. This blog post illustrates all the steps.

  • 2
    \$\begingroup\$ Are you sure that answer applies to the UK larp scene? Weapon construction and techniques vary widely between countries. In the UK, all weapons I've seen are foam and latex+isoflex weapons with a carbon fibre core. I've never seen paper mache on a weapon and would be uncomfortable with any weapons with a paper mache layer being used in a combat I was in, because I wouldn't trust the construction. Though I know weapon construction is /very/ different in the US. \$\endgroup\$
    – Racheet
    Apr 15 '15 at 15:53
  • \$\begingroup\$ @Racheet, I didn't examine all the possible different types of spraycan applied foam. The one I find readily available and have experience with are just not suitable for anything other than for props. The foam has durability issues and safety issues. \$\endgroup\$
    – RS Conley
    Apr 15 '15 at 18:53
  • \$\begingroup\$ Not only this, I'm actually not sure this material is suitable for hitting people with safely. \$\endgroup\$
    – user8248
    Apr 16 '15 at 17:10

What you need to be aware of is the safety requirements of the game that you are planning to play but these are fairly standard because most makers want to be able to work across different systems as there aren't that many LARPers so a maker wants to be able to sell to as many of them as possible.

The standard construction is a polycarbonate or carbon-fibre core with a high-density closed-cell foam ( plastazote or similar is typical ) for the shape of the weapon and latex surface layer. You may need to use softer foam for anything that is likely to be too risky with the denser foam types - tips on stabbing weapons, for example.

If you work with those materials and you make sure that you're aware of the safe distances between the core and the edge of the weapon, you should pass weapons check at most reputable systems, but until you have made a few weapons using a conventional approach it would be unwise to get too experimental- any weapon that doesn't have enough give in the materials will not be allowed on the field in most systems. If the structure crumbles then within a few blows you will be hitting people with the core, or with a core in a latex bag of foam dust, which is likewise unsafe.

The weapon in your illustration looks like a cosplay prop rather than a LARP weapon - the wooden core designed in two pieces, use of expanded foam and amount of exposed haft all suggest that it would not be combat safe- if it was being shown as a LARP weapon that is probably a mistake on the part of whoever posted it. You could make a LARP weapon that looked like that, but you wouldn't use that process.


While painting it would help minimally for keeping its shape, for use as an actual weapon it would be useless. It might survive the first blow or two but after hitting people a couple times, or something being dropped on it, it's gonna break.

  • \$\begingroup\$ Unless you plan to wrap it in steel and spikes or something, you're going to have a very hard time actually harming someone with, well, any kind of foam really. I suppose you could suffocate someone with it if you were being very creative and determined to do so. If you managed to hit them without breaking the object, you might theoretically be able to get them to hit their head by falling over (if they really really failed their irl saving throw). But in short, no, foam is extremely player safe. Just not durable. \$\endgroup\$ Apr 16 '15 at 17:50
  • 2
    \$\begingroup\$ A less durable weapon is unsafe if it falls apart quickly, though, as you're then basically hitting people with the core. \$\endgroup\$
    – glenatron
    Jun 30 '15 at 14:07

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .