UNO is a popular multiplayer card game. In each turn, a player has to play a card in their hand having the same number or color as the most recently played card. When having few people, adding virtual players to play the game can easily be done in UNO video games. However, this is a challenging task for physical UNO without computers. In this paper, we propose an unconventional protocol that can simulate virtual players using nothing but physical UNO cards. In particular, our protocol can uniformly select a valid card to play from each virtual player's hand at random, or report that none exists, without revealing the rest of its hand. The protocol can also be applied to simulate virtual players in other turn-based card or tile games where each player has to select a valid card or tile to play in each turn.

翻译：UNO是一种流行的多人纸牌游戏。在每一回合中，玩家必须从手牌中打出一张与最近打出牌数字或颜色相同的牌。当参与人数较少时，在UNO电子游戏中添加虚拟玩家参与游戏很容易实现。然而，对于无需计算机的实体UNO游戏而言，这是一项具有挑战性的任务。本文提出了一种非常规协议，仅使用实体UNO卡牌即可模拟虚拟玩家。特别地，该协议能够从每位虚拟玩家的手牌中均匀随机选择一张有效牌打出，或在无有效牌时进行报告，同时不泄露其手牌中的其余卡牌。该协议也可推广应用于其他回合制卡牌或棋类游戏中，用于模拟需要在每回合选择有效卡牌或棋子进行操作的虚拟玩家。