Rulings
Q1: What happens to cards placed face up in the security stack by effects?
They become face-up security cards that remain revealed. Other than rules that specify face-up security cards, the rules apply in the same manner as standard security cards.
Q2: What happens upon a security check for a security card that is placed face-up?
The check is performed with the card left revealed. Other than rules for cards left revealed, the rules apply in the same manner as standard security checks.
Q3: Does a card's Security effect trigger upon a security check with that card placed face-up?
Yes, it triggers.
Q4: What happens if I shuffle a security stack that includes security cards placed face-up?
Any face-up cards are placed face down, then you shuffle the cards. After shuffling, all cards are left face-down.
Data Sources
Lv.2 Puroromon BT18-004 U In-Training | Larva/X Antibody/Royal Base | - - --- Inherited: [Start of Your Main Phase] By placing 1 Digimon card with the [Royal Base] trait from your hand face up as the bottom security card, add your top security card to the hand.
Lv.2 Puroromon BT18-004 U In-Training | Larva/X Antibody/Royal Base - --- Inherited: [Start of Your Main Phase] By placing 1 Digimon card with the [Royal Base] trait from your hand face up as the bottom security card, add your top security card to the hand.
Lv.2 Puroromon BT18-004 U In-Training | Larva/X Antibody/Royal Base --- Inherited: [Start of Your Main Phase] By placing 1 Digimon card with the [Royal Base] trait from your hand face up as the bottom security card, add your top security card to the hand.
Lv.2 プロロモン BT18-004 U 幼年期 | 幼虫型/X抗体/ローヤルベース - --- Inherited: 【自分のメインフェイズ開始時】自分の手札から、特徴に「ローヤルベース」を持つデジモンカード1枚をセキュリティの下に表向きで置くことで、自分のセキュリティを上から1枚手札に加える。