A card in Dominion is informally referred to as strictly better than another if, in some sense, having or using the former confers all the same advantages as the latter as well as some added benefit, with no potential additional disadvantages. A typical reason this might happen is if one card provides more +Bazaar is strictly better than Village because the effect of Bazaar is the same as that of Village plus . Another way one card might be strictly better than another is if it offers the effect of the other as one of two or more options. For instance, once in your deck, Count is better than Mandarin since Mandarin's effect is one of the nine choices Count makes available: thus all the benefits of Mandarin are present, but in cases where the effect of Mandarin would be disadvantageous, Count makes other options available and Mandarin doesn't. Alchemist is strictly better than Laboratory because it has exactly the same effect when played, and also may give you the option of top-decking it instead of discarding it., +Buy, +Action, or than another but otherwise has the same effect, since under ordinary circumstances there is no way those additional effects can harm the player. For example,
There are numerous cases where a card has an additional effect that is usually beneficial, but in some cases may turn out to be harmful; whether such cards are considered "strictly better" may depend on context. For example, although drawing an additional card is usually desirable, it can also cause a terminal collision or a reshuffle at an inopportune time, so a card like Village may not be considered "strictly" better than a card like Necropolis for this reason in some analyses. More complicated situations also exist: for example, Harem has the same effect as Silver when played and is worth 2 more, so it might be considered strictly better than Silver; but possessing a Harem in your deck may allow you to be given a Curse by an opponent's Jester, which Silver would not. Similarly, Goons differs from Woodcutter by providing both + and a discard attack and would in most contexts be considered strictly better, but the discard attack could help an opponent by enabling their Tunnel or Menagerie. Great Hall is usually strictly better than Estate since Great Hall may be played as a cantrip, but in a deck with Baron, Estate may be more beneficial.
As the range of effects possible on Dominion cards increases, the ways those effects can fail to be uniformly "strictly" better than each other also increases. Storyteller allows you to convert + into +Cards, so if an increase in card draw isn't a strict improvement then in the presence of Storyteller neither is an increase in + . Diadem converts +Actions into + , so in the presence of Diadem and Storyteller, an increase in +Actions isn't a strict improvement either. This emphasizes that the "strictly better" concept is itself an informal rough heuristic for comparing cards to each other, not a well-defined description.
Since there are cards that reward deck diversity, it can be argued that there is no card that is in all cases strictly better than another: for example, even though Bazaar provides all the effects Village does plus extra Fairgrounds and gaining a Bazaar won't., there can still be cases when gaining a Village will increase the value of your
Similarly, cards that care about card cost may make cards that are usually worse better in specific cases: for example, Village may be more useful than Worker's Village if you have Forge with a disposable card. Therefore, when people say that one card is strictly better than another, they often mean that it has a strictly better effect.
 Implications for card design
Donald X. Vaccarino has written that a basic principle of Dominion card design is that no Kingdom card may have a strictly better effect than another with the same or higher cost. This is because, in a game with both such cards in the supply, players will buy only the better card and ignore the worse one, making the worse card's presence in the supply seemingly pointless. However, if a strictly worse card costs less than a better one, you might still buy it on turns when you don't have enough money to buy the better one. This sometimes restricts the possible design space of cards: the fact that Throne Room costs means that it is not possible to create a card that's strictly better than Throne Room unless it's strong enough to cost or more.
Indeed, even though Silver costs only, Donald X. is unwilling to give a card strictly better than Silver a cost of even .
There are a few cases of Kingdom cards that are sometimes referred to as almost strictly better at the same price:
- Count is strictly better than Mandarin once in your deck; however, Mandarin has an on-gain effect that is sometimes desirable.
- Hunting Party is better than Laboratory in most decks that don't have very many copies of strong Treasures or terminal Actions.
- Noble Brigand is better than Thief except when gaining Copper is desirable or special Treasure cards abound.
- Buying Delve is strictly better than Silver, except that Delve is an Event and in a few cases buying cards is preferable to buying Events, and Events cannot have their cost reduced.
- Ducat is strictly better than Candlestick Maker in terms of its abilities; but the fact that Ducat is a Treasure and Candlestick Maker is an Action can make Candlestick Maker more desirable in some circumstances.
Copper is in general strictly better than Abandoned Mine. However, there are some edge cases like Festival+Library engines or the unfortunate case of drawing a Throne Room without any other action card, where Abandoned Mine can be better than Copper. Also Copper and all Ruins are in general strictly better than Curse; but these are a special case since they cost and are so rarely likely to be bought anyway.
It is possible, however, for a card to be strictly better than one of the same cost in a particular Kingdom: in games with no non-terminal Action cards, Conspirator is strictly worse than many terminal silvers costing and .