Combat Systems checklist for MUDs

Calculate maximum possible damage using peak level stats, gear modifiers, and buffs to ensure the value does not exceed the variable type limit (e.g., 32,767 for 16-bit signed integers).

Scan all damage, hit-chance, and mitigation formulas for variables that can reach zero (such as Armor Class or Agility) and implement a minimum floor of 1 where they act as divisors.

Verify that a successful hit against a target with high damage reduction (DR) or armor still deals at least 1 point of damage to prevent infinite combat loops.

Test that a fast weapon (1.0s delay) and a slow weapon (4.0s delay) yield identical damage-per-second results when normalized against base stats.

Confirm that critical multipliers are applied after base weapon damage but before flat damage reduction modifiers are subtracted.

Measure the server tick rate under 50% CPU load to ensure the combat pulse (e.g., 2.0s rounds) does not drift or lag.

Verify that executing a skill (e.g., 'kick') prevents the use of other active skills for the duration of the defined cooldown period.

Test that players in a 'stunned' or 'bashed' state cannot execute movement, spellcasting, or item-use commands until the state expires.

Validate that the 'flee' command success rate is calculated using the relative level/dexterity of the combatants and consumes a movement/stamina penalty.

Ensure that skills like 'Second Attack' or 'Dual Wield' have a hard cap on the number of swings per round to prevent CPU-exhaustion exploits.

Implement and verify a 'post-stun' immunity window of at least one round to prevent players or NPCs from being permanently immobilized.

Verify that casting the same spell (e.g., 'Armor') twice does not stack the bonus, but instead refreshes the duration of the existing effect.

Confirm that if a player disconnects while in combat, their character remains in the world for a set 'link-dead' duration to prevent combat dodging.

Verify that Damage over Time (DoT) effects properly attribute the kill to the original caster for the purpose of experience gain and loot flags.

Test that elemental resistances (Fire, Cold, etc.) cannot exceed 95% to ensure that specialized NPCs remain a threat.

Verify that an NPC maintains its threat list even if the primary target leaves the room and returns within a 30-second window.

Test that NPCs flagged as 'social' correctly join combat when an ally within the same room is attacked.

Confirm the combat engine correctly differentiates between identical mob names (e.g., 'kill 2.guard') and does not default to the first index.

Verify that the administrative 'peace' command immediately clears the 'fighting' pointer for every entity in the room.

Ensure that pets or summoned creatures immediately cease combat if their owner dies or is removed from the game world.

Verify that the 'brief' command successfully toggles off flavor text and only displays numeric damage and health status.

Ensure the player's prompt (HP/Mana/MV) refreshes immediately after every combat round where a change in resources occurred.

Confirm that damage messages use distinct ANSI colors to differentiate between 'misses', 'normal hits', and 'critical hits'.

Verify that failing a skill provides a specific reason (e.g., 'Not enough mana', 'Target not in room') rather than a generic failure message.

Confirm that NPCs provide a visual health status (e.g., 'is in excellent condition') at the end of every round.

Verify that skills cannot be initiated if the current resource pool is lower than the required cost.

Cross-reference the health value stored in the character object with the value displayed in the prompt to ensure no desynchronization occurs.

Test party experience splits to ensure that total XP awarded does not exceed 100% of the mob's value due to rounding errors.

If durability is implemented, verify that weapon and armor condition decrements only on successful hits or blocks.

Verify that being 'overburdened' applies the correct penalty to hit-chance or dodge-rate in the combat loop.