I can't find this in the rulebook or reference guide: Is there an order in which things that occur during the "end of the round" are played? The reason I'm asking, after just my first play of the game, is this:

C yberdemon demon card

(2 argent) Rail Cannon: At the end of the round, perform an attack with 8 range, 2 black dice, and 4 red dice.

Sample Collection mission card
END OF ROUND: Place 1 (argent) on the demon card corresponding to each Priority Target.

Though the wording is slightly different, both mention they trigger or can be activated during the end of the round. My Cyberdemon had 1 argent before the end of the round, so the above matters to know whether or not it could use the Rail Cannon ability.

Mind you, I just played one game and have no idea if similar issues come up with other cards.

Since there's no ruling on this (And still no Errata, I'm pretty sure) I'd say that they occur in whatever order you choose in that case, or simultaneously in the case of, for example, a marine's grenade and the invader's cyberdemon.

I've got an answer from the game designer on an other forum I'm frequenting. Basically, the rules concerning this, and other conflicting situations, are addressed on page 19 of the rules reference book, under "Timing":

Quote

TIMING
If multiple game effects are resolved at the same time, the player resolving his activation chooses the order in which they are resolved.

• If multiple game effects are resolved at the same time between player activations, the invader resolves his effects first followed by any marine effects.
• If a player is using multiple effects at the same time, he chooses the order in which those effects are resolved.

- The invader cannot resolve multiple copies of the same event card at the same time.

This clears up the confusion.

Yeah that makes sense. I had a feeling it was covered somewhere, they actually did a really good job on covering bases like that.