Board Game Arena

This is my first post, so forgive me for being a noob if this question has been answered elsewhere (I couldn't find it through a quick search)...

I was just wondering, when a game gets one-sided and it's clear who the winner will be, are there any options to end the game without a penalty to someone or the game ending with no change to ELO rating?

My example of this is through realtime Reversi... at some point it becomes pretty clear who's going to win, but it still takes some time to get to that end by completing the board. I know that leaving/being expelled results in an unranked game/a penalty... One of my opponents somehow (I don't know how to do it) proposed to abandon the game, but I wasn't sure if that would render the game null or anything else.

Can anyone else shed light on this topic? ^^"

Sure, you can give the victory to your opponent in 2 players-games.

When you choose to leave a game you have some choices, between them there is one that allows you to "surrender" to your opponent (at least in games with 2 players) and give him a regular won game, without penalties for you exactly like as you finished the game losing it. But be careful, sometimes your opponent may consider it a nasty choice (i.e. if you do it at the last move of the game instead of doing the last move) so probably it's better to talk about it before doing it.

To expand on what Tejo said:

In the upper right of the screen, next to your name (with the menu that takes you to your profile), there is a leave table icon. It looks like a square with an arrow pointing right. (Sorry, I can't seem to grab the icon and insert it here.)

Clicking on that pops up a menu with various choices.

First, the warning about what happens if you quit a game in progress -- ELO penalty and your account marked with "leaves games."

Then, some choices:
Accept the consequences, and leave anyway.
Concede the game. This allows you to give the victory to the opponent in a two-player game. As Tejo noted, etiquette is to discuss it first. The ELO change will be the same as if the game had played out. You do not receive a leave penalty.
Propose to abandon the game. This requires a yes vote from all players. In this case, the system acts like the game never happened -- No ELO change, no increase in games played. This is normally reserved for drastic events (game-breaking bug, players who can't stand each other and are not willing to waste the time out-waiting each other, etc.)
And, a couple of options to close the pop-up.

Propose to abandon the game. This requires a yes vote from all players. In this case, the system acts like the game never happened -- No ELO change, no increase in games played. This is normally reserved for drastic events (game-breaking bug, players who can't stand each other and are not willing to waste the time out-waiting each other, etc.)

Just to comment this, I have also participated in a couple of games where we agreed with the other player(s) to start again after a couple of turns because none of us was happy of the beginning, so I would not say it is only for rare and "bad" cases (when it happened it was on games longer than 20-30 min, if it is for RFTG you'd better finish the game anyway )