In 2014, Inspiration gave you Advantage. You had to say so before you rolled, and if the die came up 19 anyway, you had spent it for nothing. So players sat on it, waiting for a moment that deserved it.
The 2024 rules rename it Heroic Inspiration and turn it into a reroll. You roll, you look at the die, and only then do you decide. It works on any die, not only the d20. The rule is in the free System Reference Document 5.2.1 [1].
Arthur wants every clause exact. James wants to know why he should ever keep it. This post gives both: the rule word for word, what changed from 2014, the odds, where it does the most good, and what research on rewards says about how a DM should hand it out.
The 2024 rule, word for word
From SRD 5.2.1, "Playing the Game", the Heroic Inspiration sidebar on page 7 [1]:
- Using it. "If you have Heroic Inspiration, you can expend it to reroll any die immediately after rolling it, and you must use the new roll."
- Only One at a Time. "You can never have more than one instance of Heroic Inspiration. If something gives you Heroic Inspiration and you already have it, you can give it to a player character in your group who lacks it."
- Gaining it. "Typically, GMs award it when you do something particularly heroic, in character, or entertaining. It's a reward for making the game more fun for everyone playing."
The Rules Glossary adds the hard edge: if you gain it while you already have it, "it's lost unless you give it to a player character who lacks it" [1]. Hold it and earn another, and one of them goes to a friend or goes nowhere.
Three rules give it out without the GM:
- Human, Resourceful: "You gain Heroic Inspiration whenever you finish a Long Rest" [1].
- Champion Fighter, level 10, Heroic Warrior: "During combat, you can give yourself Heroic Inspiration whenever you start your turn without it" [1].
- Advantage and rerolls: if you roll two d20s, Heroic Inspiration rerolls "one of those dice, not both of them" [1].
What changed from 2014
The 2014 rule, from SRD 5.1, "Inspiration" [2]:
| 2014 Inspiration | 2024 Heroic Inspiration | |
|---|---|---|
| What it does | Advantage on one attack roll, saving throw or ability check | Reroll any die, keep the new roll |
| When you decide | "when you make" the roll | "immediately after rolling it" |
| Which dice | d20 only | Any die: d20, damage, Hit Dice, anything |
| Earned for | Playing your personality traits, ideal, bond and flaw | Something "heroic, in character, or entertaining" |
| Holding two | "You either have inspiration or you don't" | Same, but the spare passes to a friend or is lost |
| Giving it away | Spend yours to reward another player's roleplaying | Only when you'd gain a second |
| Automatic sources in the SRD | None | Human (each Long Rest), Champion (each turn in combat, level 10) |
The 2014 version asked you to bet before you knew. The 2024 version lets you see your hand first.
The odds: same numbers, no waste
Here is the part that surprised Arthur. Rerolling a failed d20 gives exactly the same chance of success as rolling with Advantage. Both come to 1 − (chance of failing)² [3]. The difference is when you pay.
Attack rolls, where a natural 20 always hits and a natural 1 always misses:
| You need on the die | Plain roll | 2014 (Advantage) | 2024 (reroll a miss) | How often 2024 spends it |
|---|---|---|---|---|
| 6 or more | 75.0% | 93.8% | 93.8% | 25% of rolls |
| 11 or more | 50.0% | 75.0% | 75.0% | 50% |
| 16 or more | 25.0% | 43.8% | 43.8% | 75% |
| 19 or more | 10.0% | 19.0% | 19.0% | 90% |
On an easy roll, the 2014 player spent Inspiration and would have hit three times in four without it. The 2024 player keeps it three times in four and spends it only on the miss. Same payoff, a quarter of the price.
It's all fun and games until someone rolls a 1.
It stacks with Advantage, one die at a time [1]. If both d20s miss, reroll one:
| You need | Advantage | Advantage + Heroic Inspiration |
|---|---|---|
| 6+ | 93.8% | 98.4% |
| 11+ | 75.0% | 87.5% |
| 16+ | 43.8% | 57.8% |
For how Advantage gets to those numbers, see our advantage and disadvantage guide.
Where one reroll does the most good
Death saves. A character at 0 Hit Points rolls a d20 each turn: 10 or higher is a success, a 1 counts as two failures, a 20 brings you back with 1 Hit Point [1]. With nobody helping, the character dies 40.5% of the time. Hold one Heroic Inspiration and reroll the first failed save, and that falls to 23.0% [3]. One token takes almost half the deaths off the table. The coin-flip side of death saves is in Heads or Tails.
A missed attack beats a low damage die. A Fighter with a greatsword who hits 65% of the time deals 2d6 + 5, 12 on average. Rerolling a miss is worth 7.8 damage on average. Rerolling a low d6 is worth 0.75 [3]. The best damage rerolls, rerolling any die at or below half:
| Die | Average | Reroll at or below | New average | Gain |
|---|---|---|---|---|
| d6 | 3.5 | 3 | 4.25 | +0.75 |
| d8 | 4.5 | 4 | 5.50 | +1.00 |
| d10 | 5.5 | 5 | 6.75 | +1.25 |
| d12 | 6.5 | 6 | 8.00 | +1.50 |
Damage dice are the worst place to spend it, unless the one die decides whether the dragon drops. (Every player holding a d6 swears it does.)
The Champion's engine. A level 10 Champion attacks twice, and Heroic Warrior refills the token at the start of any turn it starts without one [1]. At +9 to hit against AC 17 (a 65% hit), that turns 1.30 hits a turn into 1.68: 29% more hits, every round [3]. Over a four-round fight, that's about one and a half extra greatsword hits. For the Champion, hoarding is a mistake: an unspent token refills nothing.
The Human's morning coin. Resourceful hands a Human one every Long Rest [1]. Spend it before you rest again, or the refill goes to waste. More on the other species in our D&D 2024 species guide.
How to run it well
- Decide "immediately" at your table. The rule says you reroll "immediately after rolling it" [1]. A player sees the die, not the monster's AC. Pick one before session one: reroll before the DM says hit or miss, or after. Arthur rules before; James wants after. Both are fair, if everyone knows.
- Give it for the sentence, not the list. The SRD names three triggers: heroic, in character, entertaining [1]. Don't post a price list (see the research below). Hand the token over with one line of praise: "the hireling nearly ran, and you stood with him. Heroic Inspiration."
- Make the pass-on visible. When someone earns a second, ask the table who lacks one. The rule makes the gift a moment, so let it be one.
- Track it on the sheet. A single tickbox, or a token in front of the player. Tokens get spent; tickboxes get forgotten.
Why a reroll feels better than Advantage
The near miss stings most. Medvec, Madey and Gilovich had observers rate television footage of medallists at the 1992 Barcelona Olympics. Bronze medallists looked happier than silver medallists. Silver medallists' thoughts ran to how close they came to gold; bronze medallists', to how close they came to no medal at all [4]. A 14 on a DC 15 is a silver medal. The 2024 rule lets you answer that exact roll, the one that hurts, instead of guessing in advance which roll will.
Surprise praise beats a posted reward. A meta-analysis of 128 experiments by Deci, Koestner and Ryan found that expected rewards lowered how much people chose to keep doing an activity on their own. Positive feedback raised it, both in what people chose to do (d = 0.33) and in how interested they said they were (d = 0.31) [5]. A DM who says "do three funny voices, get Inspiration" is paying for voices, and paid-for behaviour is the kind people do less of on their own. A DM who hands it over as a surprise with a sentence of praise is closer to feedback.
Giving it away makes the giver happier. Dunn, Aknin and Norton randomly assigned people to spend money on themselves or on others. By evening, the ones who spent on others were happier [6]. The 2024 rule builds that into the game: earn a second token and the only way to keep it is to hand it to a friend.
Table Talk
James: I spend mine the first time I roll under a 10. Every session. No regrets.
Arthur: On a damage die, once. For 0.75 damage.
James: It was the killing blow! Probably.
Arthur: Spend it on d20s that miss, and on death saves. That's where one reroll moves the odds by half.
James: But if I hold it, I can't pass the next one on. Spending it early is how the table gets more.
Arthur: Fine. That's the rule and the maths agreeing with you, for once.
James: Tip: when your friend gets two, cheer for the one who gets the spare. It's the best bit.
Arthur: Tip: settle "reroll before or after the DM calls it" before session one, not mid-fight.
References
- Wizards of the Coast. System Reference Document 5.2.1. 2025. CC-BY-4.0. Sections: "Playing the Game" (Heroic Inspiration, Advantage and Disadvantage, Death Saving Throws); "Character Origins" (Human, Resourceful); "Classes" (Fighter Subclass: Champion, Heroic Warrior); "Rules Glossary" (Heroic Inspiration). https://media.dndbeyond.com/compendium-images/srd/5.2/SRD_CC_v5.2.1.pdf
- Wizards of the Coast. System Reference Document 5.1. 2016. CC-BY-4.0. Section: "Beyond 1st Level" (Inspiration: Gaining Inspiration, Using Inspiration). https://media.wizards.com/2023/downloads/dnd/SRD_CC_v5.1.pdf
- DnD Dice Roller. Heroic Inspiration odds script: exact counts over every die face; natural 20 hits and natural 1 misses on attacks; death saves with no healing, reroll spent on the first failed save; Champion at +9 against AC 17 with two attacks. 2026.
- Medvec, V. H., Madey, S. F., & Gilovich, T. (1995). When less is more: Counterfactual thinking and satisfaction among Olympic medalists. Journal of Personality and Social Psychology, 69(4), 603-610. https://doi.org/10.1037/0022-3514.69.4.603
- Deci, E. L., Koestner, R., & Ryan, R. M. (1999). A meta-analytic review of experiments examining the effects of extrinsic rewards on intrinsic motivation. Psychological Bulletin, 125(6), 627-668. https://doi.org/10.1037/0033-2909.125.6.627
- Dunn, E. W., Aknin, L. B., & Norton, M. I. (2008). Spending money on others promotes happiness. Science, 319(5870), 1687-1688. https://doi.org/10.1126/science.1150952
