A free mod for Valheim, by aedenthorn.
This mod adds three config multipliers for damage taken by players, wild creatures, and tamed creatures. It also has custom multiplier lists for attackers and defenders, such as CustomAttackerDamageMult = Boar:2.5, Wolf:0.5.
It allows you to adjust the values by editing the config file using a text editor or in-game using the Config Manager. To install it, you will need the BepInEx/plugins folder, which is in the same directory as the game. To install it, just download the dll file and place it in the BepInEx/plugins folder. It will take care of the dependencies.
