Slimy helps you escape grabs

[fairyarmadillo]

Summary

Balance "Slimy mutation helps you escape grabs"

Purpose of change

Grabs check a number of factors to determine your escape chance, but one thing I realized is that they weren't checking any mutations apart from strength and possibly limb scores. Slimy is a mutation that would make sense here - fish and frogs are famously slippery, and holding onto an actual slime mutant should be pretty difficult.

Describe the solution

Having the Slimy or Viscous mutation (they're mutually exclusive) adds a flat 6% to your grab escape chance. This chance is then multiplied by the clothing_wetness_mult of the grabbed body part. This models the slime exuding from your skin and only soaking through your clothing according to its coverage and breathability.

Describe alternatives you've considered

There is an existing stopgap measure in clothing_wetness_mult that I became aware of while working on this:

    // always some evaporation even if completely covered
    // doesn't handle things that would be "air tight"
    clothing_mult = std::max( clothing_mult, .1f );
    return clothing_mult;

This means that even if you're totally covered, you'll always have a 0.6% bonus to escape grabs if you're slimy. This is pretty inconsequential and only really matters for power armor, which most mutants can't wear anyway. Since it's a preexisting issue and has a negligible impact, I don't think it needs to be addressed here. A proper fix might be to add an airtight tag to totally airtight items and check for it in clothing_wetness_mult.

The 6% was chosen after some basic testing, and could be adjusted if it's too weak or too strong. I picked a number that would still have some minor impact even if the player was clothed or lightly armored, but wouldn't be so high as to make grabs harmless while nude.

Testing

Turned on debug mode, got grabbed and escaped several times. Mutated Slimy and did the same, mutated Viscous and did the same. Saw that escape chances were properly being adjusted each time.

In testing with typical early to midgame armor setups, it was generally still adding 2 or 3% to the escape chance, which feels reasonable. Players can maximize the benefit of their slime by using lower-coverage and higher-breathability gear on their limbs, which seem to get grabbed the most and cause the most problems with escaping.

A naked slimy character with 5 Melee, a Grab Break tech, 16 strength, and Slimy was usually getting around 30% total escape chance from a torso grab by a debug strong grabber enemy, or 23% without slimy, as expected. Most characters will not be facing strong enemies while nude, so the usual escape chance for such a character would probably be in the high twenties.

Additional context

A strong grabber testing a grab against a naked slimy character.

A strong grabber testing a grab against a naked slimy character wearing a bathrobe.

A strong grabber testing a grab against a naked and non-slimy character.