Got in another 4 player game of Runewars last night (3 way tie with 5 Runes, 11 Influence points took the tiebreaker), and when I got home I needed to whip through the erratta to see which spaces should have one giant and not two. I noticed late in the erratta a question regarding the Tactical Retreat card that if the attacker has more than eight units when the TR card is played, he can "retreat his additional units as if he had won the battle".

I didn't know that a victorious attacker could "retreat" his extra units, or any units. Where in the rulebook is this articulated?

Hailnurgle said:

A hex can hold a maximum of 8 units, so if the attacker overstacks and has more than 8 surviving units at the end, the remainder must retreat. I don't have a page reference handy, but I'd start looking in the area where it says you can overstack when attacking. The attacker cannot choose to retreat if he has 8 or fewer surviving units, but he must retreat if he has more than that.

Edit: IIRC, regarding the giants, the hex on tile #2 with the giant is the one that gets two, the others each get one. Tile #2 gets 2, easy way to remember. =)

The rule you are looking for is on page 18; it's near the end of the "Movement Restrictions" section (2 paragraphs above "Diplomacy").

Note, though, that all excess units must retreat to a SINGLE area; and since this is considered a retreat, you must follow all "retreat" rules, which means you must move them to a friendly area if there is one, even if this would cause you to overstack (you'd then have to kill units). You can only retreat to an empty area if there are no friendly areas at all. This means that even if the only friendly adjacent area has 8 units already, you must retreat there and lose forces back down to 8.

Also, the excess units you are retreating are routed as normal.

But that's the price you pay for being allowed to bring in more than 8 units to fight.

Thanks to both of you for clarifying this.