You have contracted Tetanus!
On the third day after contracting Tetanus, if it has not been removed by a Priest or Healer (restoration spell or at a shrine or dedicated healer) make a Constitution Ability Check DC 15.
If the character passes the Constitution check there is no immediate effect but they must make an ability check every subsequent day subtracting the day from the roll. Eg Day 2 -2, day 3 -3. On day 21 if the character has not sought medical help they go into cardiac arrest, drop to 0 HP and must begin making death saving throws. A character can be stabilised or healed with a potion but unless medical help is sought within 24 hrs they immediately go into cardiac arrest again.
On a failed Constitution check, roll 1d6 at the start of each combat for the resulting effect. All effects stack, eg. a character can be impacted by multiple effects for the entire duration of combat.
1: Violent Seizures : roll 1d4 on a 3 or 4 re-roll on the Tetanus table adding +1 to the result. On a 1 or 2 Character is incapacitated and prone for 1d4 turns. After the seizure passes the character takes +1 levels of Exhaustion
2: Rictus Grin / Dysphagia / Lock Jaw : unable to talk & unable to cast spells with a verbal component for 1d4 turns. After the effect passes the Characters Charisma modifier is reduced to -1 for one hour (eg a Cha modifier of +2 or +3 drops to -1, a character already at -1 drops to -2)
3: Fever & Headache : unable to concentrate on spells & spells requiring concentration automatically fail for 1d4 turns. After the effect passes the Characters Intelligence modifier is reduced to -1 for one hour
4: Muscle Spasms - Back : Strength modifier is reduced to -1 for one hour
5: Muscle Spasms - Arms & Legs : Dexterity modifier is reduced to -1 for one hour
6: Diarrhoea : Violent crap-your-pants liquid poos. Spells cannot be cast or concentrated on, movement is reduced to 5 feet and Str, Dex & Cha modifiers both to -1 for 1 hour. With the exception of Restoration (greater or lesser); no spells, abilities or modifiers can improve this stomach cramping shuffle.
On Day 9 after contracting tetanus the effect duration increases from 1d4 to 1d6 turns
On Day 15 the effect duration increases from 1d6 to 1d8 turns
On day 21 if the character has not sought medical help they go into cardiac arrest, drop to 0 Hp and must begin making death saving throws. A character can be stabilised or healed with a potion but unless medical help is sought within 24 hrs they immediately go into cardiac arrest again and must repeat the death saving throws. If the character passes the death saving throws they must also roll on the Tetanus effect table if they enter combat at any stage during those 24 hours.