In Dungeons & Dragons (D&D), the term "Resistance" refers to a creature's or object's ability to halve the damage taken from a specific source or type. When a creature has resistance to a particular type of damage, such as fire, slashing, or psychic, any damage of that type inflicted upon the creature is reduced by 50%. This game mechanic is crucial for character survivability and strategic planning, both for players and Dungeon Masters.

Resistance can significantly impact combat outcomes, as it effectively makes a creature more durable against certain types of attacks. This can influence players' decisions when choosing spells, weapons, or tactics to use against resistant foes. For example, knowing that an enemy has resistance to fire damage might prompt a party to avoid using fire-based spells and instead opt for damage types the enemy is vulnerable to or has no resistance against.

The concept of resistance is balanced within the game's mechanics by vulnerability, where damage is doubled, and immunities, where damage of a certain type is completely negated. Understanding and utilizing resistance effectively can be a key factor in the success of a party's adventure.

 Sources

- [RPG Stack Exchange - How does resistance work?](https://rpg.stackexchange.com/questions/115826/how-does-resistance-work)

- [D&D Wiki - 5e SRD:Damage Resistance and Vulnerability](https://www.dandwiki.com/wiki/5e_SRD:Damage_Resistance_and_Vulnerability)

- [Reddit - r/DnD - Opinions on resistance?](https://www.reddit.com/r/DnD/comments/17kt20x/opinions_on_resistance/)

- [D&D Beyond Forums - Resistance](https://www.dndbeyond.com/forums/dungeons-dragons-discussion/rules-game-mechanics/59840-resistance)

- [Only Play Wizards - Reexamining & Revising Damage Resistance in 5e](https://onlyplaywizards.wordpress.com/2019/11/15/reexamining-revising-damage-resistance-in-5e/)

- [Quora - What is the definition of legendary resistance in Dungeons & Dragons](https://www.quora.com/What-is-the-definition-of-legendary-resistance-in-Dungeons-Dragons)