The official English rules say:
The joker card ... Played by itself, it has the highest value on the table.
Since the numbered cards have value 1-13, I initially took this to mean that jokers on their own were effectively value 14, but the phrase used in the rules leaves another interpretation. A sidebar in the rules also says:
Played by itself = highest card (>13)
Consider this case:
Mike plays a single 3 card.
Mary plays a single joker (so Mike's card gets 'snatched')
Pete now plays a single joker. What happens?
a) nothing - because Pete's single joker is the same value as Mary's single joker?
b) Mary's joker is 'snatched', because Pete's joker "has the highest value on the table" - that is - higher than every other card on the table (including Mary's joker)?
What was the intended interpretation? Are the German rules more explicit here?