For me, one of the most emotional moments in any game, television show, movie, or novel is self-sacrifice—when a character voluntarily commits an act to save many at the expense of one's self.  I don't know what it is about that one narrative technique; it always makes my eyes swell and my nose run.  And sometimes it isn't the act of self-sacrifice but the moment of choice in the character that makes it.  Occasionally, it's after the decision is made, and a character reflects on his or her life leading to that moment before finally passing.  A character looking for a reason to die doesn't generate that level of emotion with a sacrifice—vis-à-vis, Ripley in Alien 3.  I can't watch the climactic moment in The Iron Giant without leaking like the Titanic, the latter not generating that level of reaction.  Maybe it was the surge of Kamen's score, the smile on the Giant's face, or the simple utterance of the word "Superman"—even thinking about it now draws a bit of pain from the back of my eyes. 


As a storyteller, I've always wondered how I could successfully replicate that in a game.  As it turns out, it's easier than you might think.  Players I've campaigned with have often committed such selfless acts—not hard considering that a new character is a die roll away.  Dungeons & Dragons has unfortunately sucked out any emotional connection to sacrifice, given that death is only an annoying speedbump on the road to legend.  Accidentally sacrificing yourself does carry some weight, though not as much as willingly leaping yourself into harm's way, knowing you probably won't leap out. 

You might think that removing resurrection injects fear in a player, especially in an RPG or board game.  Unlike video games, there's no save point.  You don't often get a do-over.  Sure, a total-player-kill (TPK) might usher a reset of the encounter, but that's a relatively infrequent affair.  Knowing your character, the personality you have grown like a potted plant from the germ of imagination to a fully realized character sheet requite with coffee stains and eraser marks will die...forever…means more to some players than you might think.

It can also be handled poorly, when the act is forced onto a character or when the choice is blatant, presented as severely as a game show.  The typical example is the famous "diving in front of the bullet" fiasco still replicated in many TV shows.  The act is so sudden, we're hardly given a chance to absorb the impact of choice, not accounting for the cliché of the act itself.  The moment becomes as satirical as Slim Pickens riding the H-bomb.     


The option of sacrifice is the most critical aspect of the moment, often more so than even the ultimate act.  It must be handled carefully, and not handed out like PEZ to wanting masses.  The Dragonlance adventures concluded with several possible endings, one of which stipulated that a player character sacrifice themselves by jumping into a portal to seal it from the other side.  Although the sacrifice was forced, the choice was not, allowing one player to take the noble route.  Another option is the sacrificial charge, where characters run into a fight they may not make it out of.  This can work, especially if there's the slimmest chance for survival.  The effect is compounded if several characters commit to this, with only one actually falling. 

With board games, specifically cooperative games, sacrifice is often discouraged as player elimination is generally frowned upon. The trick would be to leave it up to the final few minutes and have one player decide for that session to be successful, one must be sacrificed. You'd think this would be a popular mechanic, except it often backfires, leading to a player being knocked out too early. The best situation would have such an event only occur in the end, that one decision that decides victory. And as most board games are single stand-alone sessions, that sacrificed character will likely be ready to die again next week.


This is extremely rare. 


In Sub Terra, a game where players attempt to escape a cave network, permanent death can only occur in the game's final moments as flashlights run out. On more than one occasion, a player has chosen to remain behind to help another character rather than escape, potentially dooming that individual to be prey for the creepers closing in.


This can also occur in Nemesis, or at least the fully cooperative variant; in one session we played, a player literally blew himself up with a grenade to kill the alien in that room.  In all these situations, the sacrifice came out of chance, it wasn't a situation where it would occur every session. With Forbidden Island, Forbidden Desert, and Robinson Crusoe, character death is a total game loss, but with Mansions of Madness, characters can attempt to hold off the terrors to help the mission. The common denominator with self-sacrifice in games is that it must be a game that allows it without endorsing early player elimination and we generally only see that with highly thematic narrative titles. It would be an interesting idea to include a "last stand mechanic" where one character can accomplish something glorious at the cost of not surviving to the end of the game.

Extremely rare indeed.