Since Beta 36.1, Sans has Dodge (5), which lets him avoid taking any amount of DMG 5 times. It only counts if he actually would take damage, so 0 ATK monsters won't trigger it. This number will reset if the monster is returned the player's hand or deck, similar to the lives of The Heroine.
He also has the ability to give Gaster Blasters, just like Gaster himself (until Beta 46.0). Sans adds one of them to your hand at the start of your turn, but also when you play it from your hand.
As of Beta 37.0, the Gaster Blasters themselves cost 6G to use to deal 8 damage to any monster of your choice. This can be increased to 9 by using the Science Artifact.
Sans works well in a Determination or Integrity decks since you can use Will to Fight to boost Sans' stats in early game to keep him alive and dangerous when summoned. In Integrity, Inflation will boost him, and the soul's ability can make you able to use more blasters. Using Nice Cream Guy and Bravery spells is also recommended.
Basically, boost sans' stats to make him a good card.
Using Asriel will replenish any lost dodges and restore HP if Sans' stats have been boosted.
Countering Sans is fairly easy. You can simply Silence Sans with Scarf Mouse or Nacarat Jester, use cards that do X times 1 damage, such as Undyne or Undyne's Spears or place a card that will instantly kill Sans, such as Muffet's Pet (if it wasn´t ATK boosted) Hyper Goner or Headshot. As you can see, Sans is best countered with the Justice SOUL.
- Get Dunked On (by Darky)
- So Cool (by Moonlightring)
- Angry Sans (by Moonlightring)
- Mini Rider Sans (by BlueKitty12)
- Kawaii Gaster Blaster (sold separately)
- Final Attack (by Jeffa Pegas)
- Ketchup Sans (by Jacky Bunny - Fan Artist)
- Only available through Pass Quests.
- A Welcoming Smile (by Diamaincrah)
- Blaster Power (sold seperately)
- Furry Sans (by Diamaincrah)
- Just like any other card, a Shiny Sans gives Shiny Blasters.
- Sans's cost drop to 7G in Beta 10.2 wasn't listed in the Patch Notes
- Sans is the First boss ever featured in Undercards, and uses the Ketchup Sans skin in battle.
- Sans is the First card to be both DT and Legendary. (DT is Bad Time Boss Sans)