Is there a mechanical reason why a creature who activates the Magic of Eberron psionic power forced dream (104-5) can't reset his turn to before he drew a card from the deck of many things (DMG 278-9), obviating the card's effects, then, in under an hour, have a different creature draw from that deck that card the original creature now knows is on top?
A deck of many things (both beneficial and baneful) is usually found in a box or leather pouch. Each deck contains a number of cards or plaques made of ivory or vellum. Each is engraved with glyphs, characters, and sigils. As soon as one of these cards is drawn from the pack, its magic is bestowed upon the person who drew it, for better or worse. (DMG 278 but emphasis mine)
The psionic power forced dream, in part, says
While this power is active, any time during its turn the target can choose (as a swift action) to “restart” its turn. Everything that has transpired since the start of its turn is erased, effectively allowing the target to step back a moment in time to relive the turn. Doing this ends the power’s duration.
When this effect is used, everyone and everything is reset to the state they were at when the subject’s turn began. Any spells or abilities used are available again, any damage dealt is healed, any effects incurred are negated, any objects or creatures moved are reset to their original position, and so on. The only exception to this is that any power points spent to manifest forced dream are not recovered (meaning that if you manifest the power and activate its effect in the same turn, you return to the start of the turn but you do not get back the power points you spent to manifest the power.) (MoE 104-5 but emphasis mine)
If the answer is "No, that interaction is valid according to the rules," I'm curious if there're additional reasonable house rules or interpretations beyond those below that make this particular interaction difficult or impossible (short of banning the power forced dream or removing the deck from the campaign).
- The DM can house rule that as an artifact the deck's effects are unalterable by mortal means. This is unsupported by the deck of many things's text, even if it's supported by Rule 0. I thought I'd read that nothing could predict the deck's next card and nothing could change the deck's next card, but this goes unmentioned in any Dungeon Master's Guide (1E 142-3, 2E 166-7, and 3.5E 278-9) as well as 2E's Encyclopedia Magica (379-81).
- The DM can house rule that no other creature can draw from the deck until the current creature's draws are completed. This, while elegant, isn't supported by the text.
- The DM can interpret that creatures who are nonintelligent or unintelligent, whose bodies and souls are one, or without souls cannot draw from the deck. The deck won't allow draws by constructs, elementals, outsiders, and undead, nor will it allow draws by creatures incapable of reason. This is somewhat supported by the text in that, although the void card uses psyche, the Deck of Many Things chart (DMG 278) uses soul in the void's Summary of Effect, and if the creature doesn't have a soul to lose--or can't choose to lose it--no draws for that creature. Strangely, despite all this, casting the spell summon monster I [conj] (PH 286, 288) and ordering the celestial monkey or fiendish octopus to draw remains a thing.
- The DM can interpret that the phrase The character with a deck... (DMG 278) means each creature who chooses to draw encounters the deck separately. That is, once a deck's in a creature's possession the order of the cards is, for that creature, fixed until that creature draws and the card's effects are resolved. Thus the DM secretly records the cards' initial order then new order after each draw for each creature. While this will inspire head-tilts and noggin-scratching, it's interesting--but the DM is likely to suffer horribly when the players realize the DM goes into the other room, fakes snapping a pic, and uses the void on top photo of for everybody all the time. In other words, trust might be an issue.
- The DM can interpret that drawing takes a swift action, 2 or more rounds, or even 59 minutes. Mildly unsupported by the text as there's no action given for drawing, but drawing should probably fall under Activate a Magic Item (a standard action) or possibly Retrieve a Stored Item or Pick Up an Item (both move actions) (PH 141).