Limit Breaker

You are capable of pushing your body beyond its normal physical limits. This tendency to push beyond most individuals' physical limits, endure tremendous pain, and/or take high levels of damage grants you +1 to Strength or Constitution score (or +1 to both scores upon GM approval) and these score may be raised above 20.

When taking any of the following actions or performing any of the following activities you may choose to take 1d6 damage that may not be reduced in any way and reduce your max HP by 1 to gain the corresponding benefits:

• When making a jump, you may jump a distance up to double the indicated result and you may make a running jump without having to move 10ft before the jump.
• When intentionally falling/jumping down or falling after a high jump you are not prone if the damage from the fall does not incapacitate you or, if it would, you remain at 1 HP and fall prone.
• When you use an action, reaction, or bonus action to attack using your Strength you may add your Constitution modifier to the attack in addition to Strength and deal an additional 1d6 damage. This effect lasts until the start of your next turn.
• When you would normally be able to use your reaction but have no more reactions, you may take the reaction anyway with disadvantage if it requires a roll and you do not add any ability score modifiers to the damage if it is an attack (unless you also use Limit Breaker to apply your Constitution modifier to damage assuming you are using Strength for the attack).
• When you attempt a Strength ability check you count as one size category larger than normal and add the result of the 1d6 damage you took activating Limit Breaker to the check. You may activate this multiple times for the same check up to a number of times equal to your proficiency bonus either before if you must be counted as larger to even attempt the check or after if the check would fail.
• If you would be unable to carry an object due to exceeding your carry capacity you are attempting to carry, you may add your Constitution score to your Strength score for the purposes of determining carrying capacity. You must activate this every minute you continue to carry something in excess of your normal maximum carry capacity or you drop the object/are crushed by whatever you are carrying with effects determined by the GM.
• When attempting a saving throw and failing, reroll with a bonus equal to the damage you took activating Limit Breaker (if you had advantage or disadvantage you only roll once and take the result of the reroll). You may only do this once per save.
• When holding your breath you may hold your breath a number of additional rounds equal to the combination of your Strength modifier + your Constitution modifier. You must take a cumulative 1d6 more damage every time you activate this part of Limit Breaker until you are able to take a breath but the cumulative damage may be reduced (if you use this a second time you take 1 max HP reduction , 1d6 damage that cannot be reduced and 1d6 damage that can be reduced)

Maximum Effort

Additionally once you reach level 12+ you may expend any number of hit dice, up to your maximum number remaining, rolling them taking the result of the roll as damage that may not be reduced in any way (though if it would incapacitate you it leaves you at 1 HP and incapacitates you for a number of rounds equal to the number of hit die you expended on the end of your turn) to gain the following effects (no matter how many hit dice you expend you must complete a short or long rest to use Maximum Effort again):

• Gain advantage on all rolls during the turn you activate Maximum Effort even if you would have disadvantage normally.
• You reroll natural 1s on the turn you active Maximum Effort, on subsequent rounds for 1 minute natural 1s do not automatically fail if you expended at least a number of hit dice equal to your proficiency bonus.
• Add the number of hit dice expended to your attack roll and add the result of the rolled hit dice to the damage dealt, rolling the hit dice again as bonus damage dice if the attack is a critical hit (this is applied the first time you hit after using Maximum Effort and lasts until the encounter ends or you lad a hit). On subsequent attacks add half the hit dice you expended (rounded down) to attack rolls and half the number of hit dice expended as bonus damage dice (rounded down) for one minute if you expended at least a number of hit dice equal to your proficiency bonus.
• Increase your effective Strength score for the purposes of carry capacity and Strength ability checks by an amount equal to the number of hit dice expended for one hour.
• Heal an amount of HP equal to the number of hit dice expended at the start of each of your turns for one minute.
• Count as a creature one size category larger (minimum large) for one hour or two size categories larger (minimum Huge) if you expended a number of hit dice equal to your proficiency bonus or more.
• You may hold your breath a number of additional minutes equal to the number of hit dice expended before needing to take a breath. This lasts one hour.

(While you can nickel and dime your hit dice expenditure to get more than 2 daily uses out of the ability and while you do get the use of Maximum Effort back on short rest, players are encouraged to use this more for cinematic/dramatic effect going as far as to expend all their hit dice when the odds are against them or they need more of a boost than the regular Limit Breaker provides rather than something to be used between every short rest for a lesser effect)