Paula and Ace had been dating, but the king refuses to wed them. Then, Paula gets kidnapped and only Ace knows how to save her, forcing the king to reluctantly recruit him. The king then agrees to wed the couple upon Paula's rescue.
The princess is secretly a lesbian and does a poor job of disguising her disappointment at being Ace's prize.
The princess is a gonk and Ace really really doesn't find marrying her a reward.
Zig Zagged: Paula was actually in love with Lord Romand. Romand's defeat makes her resent Ace.
Averted: There are no available princesses to marry, or the marriage rules prevent Ace (possibly he's actually a woman in disguise) from qualifying for the match.
Enforced: "We've got an entire line of Bridal Dreams Paula dolls to launch, so this has to end with her getting married."
Lampshaded: "If you wish to marry me, sir knight, you must earn my father's trust. Slaying a couple of dragons ought to do it."
Invoked: Princess Paula or her father want to make certain the next king is suitably brave, compassionate, and skilled, and they set up trials which only such a person could overcome.
Exploited: Ace is actually a Emperor Evulz in disguise; he set up a reasonable facsimile of a threatening army, just enough to get the citizens of King Goodland's kingdom seriously worried, and then defeated it himself with ease to win the hand of Princess Paula. Now he's in line to inherit The Kingdom...
"You'll take this sack of gold and be satisfied."
"I'm flattered, Your Majesty, but I have a girl back home... Can't I just have a sack of gold or something?"
Discussed: "And the winner gets.." "The princess's hand in marriage?" "How did you know?"
Conversed: "Is this supposed to be an adventure or a matchmaking service?"
Just because Ace is a hero doesn't mean he makes a good ruler.
Princess Paula isn't too thrilled at being forced to marry some uncultured commoner, either, hero or not.
Paula persuades him to put most of the power in her hands, because she is more familiar with court; then, she finds that his outside point of view often lets him see what others miss, so she relies heavily on his advice.
Before succeeding King Goodland, Ace learns politics and trains himself to be a good ruler while bonding with Princess Paula to where they now genuinely love each other.
Played For Laughs: Ace learns that Paula was offered only because she had no chance of marrying otherwise. Then he learns that she was impossible to marry off because she is sharp-tongued and witty. He loves it.
Played For Drama:
Ace was not aware this was being offered when he started out; he already hassomeone he's interested in, and isn't sure if he wants to rule... but King Goodland has already ordered that The Hero be brought before him to recieve his reward...
Although Ace has personally slain Emperor Evulz, there remain remnant's of the Evulz regime (such as Evulz' advisor, Sir Trustmenot), who have gone into hiding since the close of the war. And although most of the population are glad to see Evulz' reign of terror come to an end, there remains a certain proportion of the country's population who were sympathetic to Evulz and wish to see his ideals come to fruition.
Ace was appointed by King Goodland to take the throne that he personally vacated Evulz of for the purpose of rebuilding the country into a peaceful ally. Although King Ace took measures to screen out members of the Evulz regime from his regime, he could not divine the true intentions of those who served him directly. The following year enjoyed sweeping economic reforms, a bumper crop, and an artistic renaissance. And even those who held to Emperor Evulz' ideals grew silent, as if the kingdom's prosperity had proven Evulz wrong all along.
11 months since Evulz died, King Ace receives a report of a rogue military faction calling itself the Dark Thorn Revolutionary Movement. DTRM has apparently been filling it's ranks with Evulz sympathizers and may be planning an attack in the future. In response, King Ace orders the DTRM disbanded, and 3 days later, he receives a report that the DTRM has scattered, although there is no longer any way to identify every member of DTRM.
On the one year anniversary of Evulz' defeat in combat, without warning, a never-ending stream of soldiers in black armor storm the throne room, identifying themselves as DTRM. They quickly overwhelm the royal guards. And King Ace's personal guard whisks Ace and Queen Paula to a distant safe-house.
While Ace tries to figure out how the Dark Thorn could still be active, the guard grabs Ace's old Infinity+1 Sword, and explains everything that he knows. 1: The report of Dark Thorn's defeat was a forgery. 2: Dark Thorn had already infiltrated the castle. The royal staffer was among Dark Thorn's founding members. And he had little trouble putting double agents in key security positions. 3: And the personal guard finally introduced himself: Sir Trustmenot. The rest ishistory.