Cthulhu Dark is 4 pages (including title page, so 3 pages of rules) and is a far more complete game in that it establishes who has what say, how to resolve conflicts at all times, good guidance on how to use the conflict resolution system, and some strong genre points of logic (you die if you fight mythos creatures).
Just elaborating a bit on this:
The basic action resolution rule for Cthulhu Dark is
To know how well you do at something, roll . . . your highest die shows how well you do. On a 1, you barely succeed. On a 6, you do brilliantly. [An example follows.]
So unlike the playloop posted by
@Malmuria upthread, a player can do more than just declare an action: when they declare an action, it succeeds. But the die roll can licence introduction of a complication corresponding do the degree of falling short of brilliance in execution. The rules also say
Who decides when it’s interesting to know how well you do something. . . . Decide the answers with your group. Make reasonable assumptions. For example, some groups will let the Keeper decide everything. Others will share the decisions.
The game is clearly aware of the issue that it
matters, to RPG play, who gets to say what. And offers some approaches.
Then there is the rule for failure:
If someone thinks it would more interesting if you failed, they describe how you might fail and roll a die. . . .
If their die rolls higher than your highest die, you fail, in the way they described. If not, you succeed as before, with your highest die showing how well you succeed. . . .
To compete: everyone who is competing rolls their dice. Whoever gets highest wins. [There's also a rule for breaking ties.] . . .
Who decides whether you might fail?
Decide the answers with your group. Make reasonable assumptions. For example, some groups will let the Keeper decide everything. Others will share the decisions.
It's clear, here, that there is no rule letting anyone stipulate
automatic failure. When I've played Cthulhu Dark, the possibility of failure has generally been a GM matter. I can't recall if it's ever come from a player; the most obvious context for that, thinking about it now, would be if another PC is trying to mess with that player's stuff (eg break into their house, get information from their employer, etc).
But anyway, there is very little in common between this and Dark Empire except both are short and use d6s for their rolls!
An EDIT to this:
How does Cthulhu Dark handle the examples beloved of criticisms of player agency, like the action declaration
I ask him to give me all his money? First, in practice I think this sort of thing is unlikely to occur without a context that locates it within the fiction, given the fairly tight genre focus of the game. But second, this seems like it's not humanly possible! And so that die won't be in the pool. But an occupation die might be (eg if the character's occupation is
Grifter) and so might the Insanity die be.
Because there is no way for a player to guarantee unalloyed success in this system (which contrasts with, say, the standard D&D approach to using gp to buy things), changing the fictional positioning so that the PC has all of someone else's money won't break the game. It will just open the door to resolving action declarations that involve spending lots of money. But if such a thing is done very poorly then the accompanying complication might include spending too much, or dropping one's wallet into the river while paying, or . . .
Dark Empire is less clear about this, in my view. It has the player choose both a wealth level and 4 pieces of gear, without explaining how these are related as components of fictional positioning and/or considerations for action resolution.